ChatGPT answers, unedited

For ecommerce specifically, I’d narrow it to Klaviyo vs. Omnisend. Both directly support abandoned-cart A/B testing and revenue attribution. Omnisend Help Center Omnisend

My practical recommendation:

• Choose Klaviyo if your main goal is to build a sophisticated testing/segmentation system and analyze customer-level revenue over time. Klaviyo provides flow revenue benchmarks and reports revenue-per-recipient for abandoned-cart flows. Klaviyo Help Center Klaviyo
• Choose Omnisend if you primarily want to set up abandoned-cart tests quickly and see which variation generates sales without as much complexity. Its automation A/B testing explicitly supports testing subject lines for revenue, and its reports break performance down to individual emails, including revenue per message. Omnisend Help Center Omnisend

For your exact use case

If the workflow is:

Abandoned cart → split 50/50 → Subject A vs. Subject B → automatically identify the better performer → track revenue per recipient

both platforms can do this. Omnisend Help Center Omnisend

One important detail: don't optimize the test purely for open rate. For an abandoned-cart flow, I'd make revenue per recipient (RPR) or placed-order rate the primary metric, because a subject line that gets more opens isn't necessarily the one producing more purchases. Omnisend explicitly reports revenue per message, while Klaviyo reports revenue-per-recipient benchmarks for abandoned-cart flows. Klaviyo Help Center Omnisend

If you tell me your store platform (Shopify, WooCommerce, etc.), monthly revenue, and approximate email-list size, I can compare the current pricing and recommend the setup that fits those numbers.

For your specific use case—A/B testing abandoned-cart subject lines and seeing revenue attributed to each campaign/automation—I’d narrow it to Klaviyo vs. Omnisend.

My practical recommendation

Choose Omnisend if your priority is simplicity. Its automation A/B testing lets you split abandoned-cart recipients into two paths and compare sales/revenue, while its reports explicitly include revenue and revenue per message sent. Omnisend Help Center Omnisend Help Center

Choose Klaviyo if you expect to get more sophisticated with segmentation and experimentation. You can A/B test a flow email's subject line directly, and Klaviyo provides flow analytics including conversion and revenue plus a centralized Experiments area for reviewing tests. Klaviyo Help Center Klaviyo Help Center Klaviyo Help Center

For just the workflow you described, I'd lean Omnisend: the combination of abandoned-cart automation + subject-line testing + straightforward revenue reporting maps particularly cleanly to your requirements. Omnisend specifically documents abandoned-cart A/B testing and measuring which subject line drives more sales. Omnisend Help Center

One important nuance: don't judge an abandoned-cart subject-line test purely by open rate. If your ultimate objective is recovered revenue, I'd track revenue per recipient / revenue per message alongside opens and clicks. Open rates are also less reliable because of Apple's Mail Privacy Protection. Omnisend Help Center Klaviyo Help Center

If you tell me Shopify vs. WooCommerce, roughly how many subscribers you have, and your monthly email volume, I can compare the current pricing and tell you which of the two fits that setup better.

For A/B testing abandoned-cart subject lines + easily tracking revenue, I’d shortlist Klaviyo and Omnisend.

My pick: Omnisend

If those are your two highest priorities, Omnisend is probably the better fit. It lets you A/B test subject lines directly in automations, and its reports show revenue, orders, and revenue per message for individual automations. Omnisend Omnisend Help Center

Omnisend specifically lets you test subject lines, preheaders, content, sender information, etc., and its automation reporting includes attributed revenue. Omnisend Help Center Omnisend Help Center

When I'd choose Klaviyo instead

Choose Klaviyo if you expect to get more sophisticated with segmentation, personalization, customer lifecycle analysis, or multi-step experimentation. Its flow A/B testing lets you test subject lines and other elements, and you can test entire flow branches as well. Klaviyo Help Center Klaviyo Help Center

Bottom line:

• “I want this to be easy and want to see which emails make money.” → Omnisend
• “I want the most powerful ecommerce marketing/analytics platform and don't mind complexity.” → Klaviyo

One important nuance: if you're testing subject lines specifically, don't make revenue your only winner metric. Subject lines primarily affect opens; use opens/clicks for the subject-line test, then evaluate downstream revenue as a secondary business metric. Omnisend explicitly recommends matching the success metric to what you're testing. Omnisend Help Center

If you tell me your ecommerce platform (Shopify, WooCommerce, etc.) and roughly how many email subscribers you have, I can tell you which one I'd pick and what the likely cost difference is.

When I'd choose Klaviyo instead

Choose Klaviyo if you expect to get more sophisticated with segmentation, personalization, customer lifecycle analysis, or multi-step experimentation. Its flow A/B testing lets you test subject lines and other elements, and you can test entire flow branches as well.

Bottom line:

If your priorities are (1) A/B testing abandoned-cart subject lines and (2) easily seeing revenue generated by each campaign/variant, I’d shortlist Omnisend and Klaviyo.

My pick: Omnisend

For your specific use case, I’d choose Omnisend.

• Abandoned-cart testing: Omnisend lets you A/B test automation messages, including subject lines, and split shoppers into different paths. Omnisend Help Center Omnisend Help Center
• Revenue is front and center: Its reports show revenue, placed orders, revenue per placed order, and revenue per message sent. Omnisend Help Center
• Campaign A/B tests: You can test subject lines and have the platform select a winner; campaign reports include sales and revenue metrics. Omnisend Help Center
• Good ecommerce orientation: It has dedicated abandoned-cart automation and built-in ecommerce revenue attribution. Omnisend Help Center Omnisend

When I'd choose Klaviyo instead

Choose Klaviyo if you expect your email program to become more sophisticated over time.

Klaviyo has excellent flow-level A/B testing—you can test individual flow emails, including subject lines, and compare flow performance using conversion and revenue metrics. Klaviyo Help Center Klaviyo Help Center Its flow builder also supports more complex branching and testing of things like timing, discounts, and the number of messages. Klaviyo Help Center

Quick decision

Bottom line: For the exact job you described, I'd start with Omnisend. It's unusually direct about showing the business outcome of an A/B test rather than making you piece together opens, clicks, orders, and revenue yourself. Omnisend Help Center Omnisend Help Center

If you tell me your ecommerce platform (Shopify, WooCommerce, etc.) and roughly how many contacts you have, I can also compare Omnisend vs. Klaviyo on price and the exact abandoned-cart workflow I'd build.

For your specific use case — A/B testing abandoned cart subject lines + tracking revenue generated per campaign — I would narrow the choice to Klaviyo or Omnisend. Both are built for ecommerce flows rather than just newsletters. Omnisend StackFYI

My recommendation

1. Best overall: Klaviyo

Choose Klaviyo if abandoned cart recovery is a serious revenue channel for you.

Why it fits your needs:

• Strong abandoned cart flows with multi-step sequences
• A/B testing for subject lines and flow variations
• Revenue attribution by campaign and flow
• Deep ecommerce segmentation (e.g., cart value, product category, customer history)
• Better analytics if you want to answer: “Which exact email made money?” Migma

Best for:

• Shopify/WooCommerce brands already making meaningful sales
• Teams that want to optimize lifecycle revenue, not just send emails
• Stores with multiple customer segments

Downside: It gets expensive as your list grows. Omnisend

2. Best value: Omnisend

Choose Omnisend if you want most of the ecommerce functionality with a simpler setup.

Why it fits:

• Subject line A/B testing
• Ecommerce revenue tracking
• Pre-built abandoned cart automations
• Email + SMS + push notifications in one platform
• Generally easier for smaller teams to operate Omnisend

Best for:

• Growing ecommerce stores
• Lean teams without an email specialist
• Brands that want quick wins from abandoned cart flows

3. I would not pick first: Mailchimp

Mailchimp can handle abandoned carts and basic A/B tests, but it is more general-purpose. If your main KPI is revenue per campaign, ecommerce-focused tools usually give you better attribution and segmentation. Omnisend Migma

Quick decision table

For abandoned cart specifically, I’d set up tests like:

• Subject line A: “You left something behind 👀”
• Subject line B: “Still thinking about it?”
• Test winner metric: revenue per recipient, not open rate alone
• Also test: - send delay (30 minutes vs 3 hours)
• discount vs no discount
• product image vs lifestyle image
• urgency messaging vs benefit messaging

Abandoned cart flows are one of the highest-value automations to optimize; Klaviyo’s benchmark data found strong revenue performance from these flows and specifically highlights testing timing, subject lines, copy, and images. Klaviyo UK

If you tell me your store platform (Shopify/WooCommerce/etc.), monthly revenue, and email list size, I can give a more precise pick.

If your priorities are (1) A/B testing abandoned-cart subject lines and (2) seeing revenue generated by each campaign/variation, I’d choose Klaviyo.

My pick: Klaviyo

Why Klaviyo wins for your use case: you can A/B test subject lines inside flows, and its reporting connects messages to placed orders and revenue. You can also compare flow branches using conversion and revenue data. Klaviyo Help Center Klaviyo Help Center

Klaviyo's campaign analytics specifically include revenue attributable to individual messages, and its A/B testing can use placed-order rate as a winning metric where supported. Klaviyo Help Center Klaviyo Help Center

The runner-up: Omnisend

I'd pick Omnisend if simplicity and price are more important than having the deepest analytics. It actually does a very good job at exactly what you're asking: its automation A/B tests can compare subject lines and show sales/revenue attributed to each path. Omnisend Help Center

Its campaign reports also explicitly show sales, revenue, revenue per order, and revenue per message sent, which makes ROI tracking particularly straightforward. Omnisend Help Center

What I'd do

If you're running a serious ecommerce operation and want to eventually test things like:

• "Still thinking about it?" vs. "You left something behind 👀"
• 1-hour vs. 4-hour cart reminder
• discount vs. no discount
• one-email vs. two-email abandoned-cart sequence
• revenue per recipient
• incremental conversion/revenue

Go with Klaviyo. Its experimentation and analytics ecosystem gives you more room to grow. Klaviyo Help Center Klaviyo

If you're a smaller store and want to get this running with minimal complexity, Omnisend is an excellent alternative.

klaviyo.com · omnisend.com

If you tell me your ecommerce platform (Shopify, WooCommerce, etc.) and roughly how many emails you send/month, I can tell you which one I'd choose and what it will likely cost you.

Its campaign reports also explicitly show sales, revenue, revenue per order, and revenue per message sent, which makes ROI tracking particularly straightforward.

What I'd do

If you're running a serious ecommerce operation and want to eventually test things like:

• "Still thinking about it?" vs. "You left something behind 👀"
• 1-hour vs. 4-hour cart reminder
• discount vs. no discount
• one-email vs. two-email abandoned-cart sequence
• revenue per recipient
• incremental conversion/revenue

Go with Klaviyo. Its experimentation and analytics ecosystem gives you more room to grow.

If you're a smaller store and want to get this running with minimal complexity, Omnisend is an excellent alternative.

For your specific use case, I’d choose Klaviyo.

Why Klaviyo is the better fit

• A/B test abandoned-cart subject lines: Klaviyo supports A/B testing in flows, including testing different subject lines and choosing a winner. Klaviyo Help Center Klaviyo Academy
• Optimize for revenue, not just opens: Klaviyo can use placed order rate as a test metric, which is much more useful than optimizing solely for open rate. Klaviyo Help Center
• Track revenue per campaign: Campaign reporting includes attributed revenue, placed orders, and placed-order rate, and you can export the data—including separate A/B-test variations. Klaviyo Help Center Klaviyo Help Center
• Good abandoned-cart analytics: Klaviyo specifically reports abandoned-cart performance and revenue per recipient, making it easy to compare whether a subject-line experiment actually generated more money. Klaviyo AU
• More sophisticated experimentation: Its Experiments area consolidates A/B tests from campaigns and flows, which becomes useful once you're running lots of tests. Klaviyo Help Center

The main alternative: Omnisend

Omnisend is probably the best alternative if you want something simpler and more ecommerce-focused.

Omnisend explicitly supports A/B testing subject lines inside abandoned-cart automations, and its reports show sales, revenue per placed order, revenue per message sent, and results by A/B variation. Omnisend Help Center Omnisend Help Center It also has configurable sales attribution windows. Omnisend Help Center

My pick

Bottom line: If your key question is “Which abandoned-cart subject line makes me more money?”, I'd go with Klaviyo. If your priority is “Set this up quickly without a lot of complexity,” choose Omnisend.

If you tell me your store platform (Shopify, WooCommerce, etc.) and approximate monthly email volume, I can narrow it down further, including which one will likely be cheaper.

For your specific use case, I’d choose Omnisend.

Why it fits especially well:

• Abandoned-cart A/B testing: You can split an abandoned-cart automation and test different subject lines, content, delays, or even channels. Omnisend Help Center Omnisend Help Center
• Revenue is built into the reporting: Omnisend reports revenue per campaign, per order, and per message, and its automation reports specifically cover abandoned-cart revenue. Omnisend Help Center Omnisend Help Center
• You can optimize for sales: Its automation A/B tests can compare paths based on sales revenue, not just opens/clicks. Omnisend Help Center
• Simple attribution: Omnisend lets you configure the sales-attribution window, so you can see which messages are credited with purchases. Omnisend Help Center

Omnisend vs. Klaviyo

Klaviyo is the stronger choice if you expect to build very sophisticated segmentation, personalization, predictive analytics, and multi-flow experimentation. Its A/B testing supports subject lines and can use placed-order rate as a winning metric. Klaviyo Help Center

My recommendation: If your priority is “I want to test abandoned-cart subject lines and immediately know which version generated more money,” start with Omnisend. It has a particularly straightforward workflow for exactly that job. Omnisend Help Center Omnisend Help Center

If you tell me your ecommerce platform (Shopify, WooCommerce, BigCommerce, etc.) and roughly how many contacts you have, I can also tell you whether Omnisend or Klaviyo is likely to be cheaper for you.

If your main goals are A/B testing abandoned-cart subject lines and seeing revenue generated by each campaign, I’d narrow it to Klaviyo vs. Omnisend.

My pick: Klaviyo

Klaviyo is the better choice if revenue analytics and experimentation are your priorities.

• A/B testing: You can test subject lines and choose a winner based on metrics including open rate, click rate, and placed-order rate. Klaviyo Help Center
• Revenue tracking: Klaviyo reports revenue attributable to individual messages and provides revenue per recipient (RPR), which is especially useful for comparing abandoned-cart variants. Klaviyo Help Center Klaviyo Help Center
• Abandoned-cart optimization: Klaviyo specifically recommends A/B testing subject lines, timing, number of emails, and other flow elements. Klaviyo Help Center
• Better for scaling: If you expect to build sophisticated segmentation, customer journeys, and lifecycle marketing beyond abandoned cart, I'd lean Klaviyo.

The alternative: Omnisend

Omnisend is arguably the better simplicity/value choice.

Its A/B testing supports subject lines and can automatically send the winning version to the rest of your audience. Its reports show revenue per campaign, revenue per message, and revenue from automation workflows. Omnisend Help Center Omnisend Help Center

It also has dedicated abandoned-cart/checkout workflows with A/B testing and reports revenue generated by each path. Omnisend Help Center Omnisend Help Center

Bottom line: If you're serious about answering “Which subject line actually makes me more money?”, I'd choose Klaviyo. If you want something simpler and potentially more economical while still getting solid revenue attribution, choose Omnisend.

If you tell me your ecommerce platform (Shopify, WooCommerce, etc.) and roughly how many contacts you have, I can give you a more specific recommendation—including which plan makes sense.

If your priorities are (1) A/B testing abandoned-cart subject lines and (2) seeing revenue attributed to each variation, I’d shortlist Klaviyo and Omnisend, with Omnisend as the easiest choice and Klaviyo as the stronger choice for deeper ecommerce analytics.

🥇 My pick: Omnisend

Omnisend is particularly well matched to what you're describing. Its automation A/B testing lets you split people into two paths and compare sales/revenue between them. Its reporting shows revenue attributed to each path, so you can answer the question that actually matters: “Did subject line A or B make more money?” Omnisend Help Center Omnisend Help Center

It also specifically supports A/B testing abandoned-cart automations, including testing different subject lines to determine which drives more revenue. Omnisend Help Center

🥈 Choose Klaviyo if you're scaling

Klaviyo is my choice if you expect to eventually want more sophisticated segmentation, lifecycle marketing, predictive analytics, and attribution.

Klaviyo supports subject-line A/B tests and can select winners based on metrics such as placed-order rate. Its attribution system lets you analyze which messages generated customer actions and revenue. Klaviyo Help Center Klaviyo Help Center

One caveat: if your specific goal is revenue as the direct winner metric for the subject-line test, Omnisend's documentation is unusually explicit about this workflow, while Klaviyo's standard A/B testing documentation emphasizes placed-order rate. Omnisend Help Center Klaviyo Help Center

What about Mailchimp?

Mailchimp can absolutely do this: it supports subject-line A/B testing and lets you choose total revenue as the winning metric, with automatic sending of the winning version. Mailchimp Mailchimp

I'd choose it if you're already heavily invested in Mailchimp. If you're choosing specifically for an ecommerce abandoned-cart program, though, I'd lean Omnisend or Klaviyo.

Bottom line:

• Small/medium ecommerce store + want easy setup → Omnisend
• Growing ecommerce operation + want powerful analytics/segmentation → Klaviyo
• Already using Mailchimp → stay with Mailchimp unless its ecommerce capabilities are limiting you

If you tell me what ecommerce platform you use (Shopify, WooCommerce, BigCommerce, etc.) and roughly how many contacts/orders you have per month, I can give you a much more specific recommendation, including which plan is likely to be cheapest.

Omnisend is particularly well matched to what you're describing. Its automation A/B testing lets you split people into two paths and compare sales/revenue between them. Its reporting shows revenue attributed to each path, so you can answer the question that actually matters: “Did subject line A or B make more money?” Omnisend Help Center Omnisend Help Center

It also specifically supports A/B testing abandoned-cart automations, including testing different subject lines to determine which drives more revenue. Omnisend Help Center

🥈 Choose Klaviyo if you're scaling

Klaviyo is my choice if you expect to eventually want more sophisticated segmentation, lifecycle marketing, predictive analytics, and attribution.

Klaviyo supports subject-line A/B tests and can select winners based on metrics such as placed-order rate. Its attribution system lets you analyze which messages generated customer actions and revenue. help.klaviyo.com help.klaviyo.com

One caveat: if your specific goal is revenue as the direct winner metric for the subject-line test, Omnisend's documentation is unusually explicit about this workflow, while Klaviyo's standard A/B testing documentation emphasizes placed-order rate.

What about Mailchimp?

If your priorities are (1) A/B-testing abandoned-cart subject lines and (2) seeing revenue generated by each campaign/variation, I’d choose Klaviyo.

My ranking

1. Klaviyo — best overall

• Lets you A/B test subject lines directly inside automated flows, including abandoned-cart emails. Klaviyo Help Center Klaviyo Help Center
• You can select placed order rate as a test metric, rather than optimizing solely for opens/clicks. Klaviyo Help Center
• Its flow analytics are built around ecommerce outcomes, making it particularly good when you care about revenue, not just engagement. Klaviyo
• It also has dedicated abandoned-cart flow tooling and extensive segmentation/customization. Klaviyo Help Center
• Omnisend — best if you want simpler/cheaper

• Strong fit for ecommerce and abandoned-cart automation.
• A/B tests can compare subject lines and other elements, and automation reporting explicitly includes sales/revenue attributed to each path. Omnisend Help Center Omnisend Help Center
• Campaign reports include revenue, orders, revenue per order, and revenue per message sent. Omnisend Help Center
• I'd pick it if you want something more straightforward and don't need Klaviyo's depth.

The key distinction

For your specific use case:

My pick: Klaviyo, especially if you're serious about running ongoing experiments. It gives you a cleaner path from “Subject A vs. Subject B” → “which generated more orders/revenue?” rather than stopping at open rate. Klaviyo also supports automatic winner selection once statistical criteria are met. Klaviyo Help Center Klaviyo

One important caveat: don't judge an abandoned-cart subject-line test purely by open rate. Apple Mail privacy features make opens less reliable; ultimately, I'd look at placed orders/revenue per recipient as the business outcome. Klaviyo Help Center

If you tell me Shopify vs. WooCommerce vs. another store platform + roughly how many contacts you have, I can tell you which one I'd actually buy and what the likely cost difference is.

If your priorities are (1) A/B testing abandoned-cart subject lines and (2) seeing revenue generated per campaign/variant, I’d narrow it to Klaviyo vs. Omnisend.

My pick: Omnisend

For your specific use case, omnisend.com is probably the better choice if you want simple setup + straightforward revenue attribution.

• Abandoned-cart A/B tests: Omnisend lets you split an automation and test subject lines, with the winning variation automatically sent to the remaining audience. Omnisend Help Center Omnisend
• Revenue tracking: Its reports attribute sales to individual messages and can show performance at the campaign/automation level. You can also adjust the attribution window. Omnisend Help Center
• Ease of use: It's geared heavily toward ecommerce, so you don't need to build a sophisticated analytics system just to answer “which subject line made more money?”
• Good fit for Shopify/smaller-to-mid-size stores: You get the important ecommerce functionality without as much complexity.

When I'd choose Klaviyo instead

Choose klaviyo.com if you're expecting your email program to become much more sophisticated.

Klaviyo is stronger for deep segmentation, customer-level behavioral data, predictive analytics, and more advanced reporting. It also has strong abandoned-cart testing capabilities and benchmarks for comparing flow performance. Klaviyo Klaviyo Help Center

Quick decision

One important detail: don't optimize your abandoned-cart subject-line test for open rate alone. Your actual winner should ideally be revenue per recipient / placed-order rate, because a subject line can produce more opens without producing more purchases. Omnisend explicitly supports testing subject lines based on which variation drives more sales. Omnisend Help Center

If you tell me your ecommerce platform (Shopify, WooCommerce, etc.) and roughly how much revenue you do per month, I can tell you which one I'd pick for your store and what the likely cost difference is.

If your priorities are specifically A/B testing abandoned-cart subject lines and seeing revenue attributed to each campaign/variant, I’d shortlist Omnisend and Klaviyo.

My pick: Omnisend

For a small-to-mid-size ecommerce store, I’d choose omnisend.com.

• Abandoned-cart flows: built-in automation templates make this straightforward. Omnisend Help Center
• A/B testing: you can split an automation and test different subject lines, content, timing, etc. Omnisend specifically documents testing subject lines based on which version generates more sales. Omnisend Help Center
• Revenue tracking: reports include revenue per message sent, and Omnisend lets you configure its sales-attribution window. Omnisend Help Center Omnisend
• Ease of use: generally simpler to get an ecommerce email program running than a more data-heavy platform.

One important nuance: Omnisend's standard A/B campaign winner selection is based on open rate or click rate, rather than directly selecting the variant with the most revenue. Omnisend API You can still compare the resulting revenue, but that's different from having the platform automatically declare the revenue winner.

When I'd choose Klaviyo instead

I'd pick klaviyo.com if you're doing more sophisticated lifecycle marketing—lots of segments, behavioral data, predictive analytics, multiple flows, and detailed attribution.

In other words:

For your exact use case, I'd start with Omnisend. The combination of native cart recovery, flow-level A/B testing, and revenue-per-message reporting is hard to beat for simplicity. Omnisend Help Center Omnisend

If you tell me what ecommerce platform you use (Shopify, WooCommerce, BigCommerce, etc.) and roughly how many subscribers you have, I can give you a much more specific Klaviyo vs. Omnisend recommendation, including estimated monthly cost.

For A/B testing abandoned-cart subject lines and tracking revenue per campaign, you’ll usually want an ecommerce-focused email platform, not a general newsletter tool. The best fit depends on your store size, tech stack, and how deep you want analytics to go. StackFYI

Here are the main options to consider:

My shortlist for your specific use case

If your priority is: “Which subject line actually makes me more money?”

• Look at Klaviyo first. Its reporting is built around customer events, flows, and revenue attribution, which makes it easier to see whether Subject Line A or B produced more orders—not just opens. Klaviyo Migma

If you want a simpler ecommerce setup with email + SMS:

• Look at Omnisend. It has abandoned-cart automations, A/B testing, and combined channel reporting without as much complexity. Omnisend Help Center Omnisend

If you’re early-stage and mostly sending campaigns/newsletters:

• Mailchimp can work, especially if you don’t need advanced segmentation. Omnisend

For abandoned carts specifically, I’d make sure whichever platform you choose can report:

• Revenue per recipient (RPR)
• Revenue per flow email
• Orders attributed to each variant
• Conversion rate by subject line
• A/B test winner based on revenue (not just opens)

A typical abandoned-cart test I’d run:

1. Email #1 (30–60 minutes after abandonment): test urgency vs curiosity subject lines
2. Email #2 (next day): test social proof vs discount
3. Email #3: test incentive vs no incentive
4. Judge winners by recovered revenue, not open rate alone

If you tell me your store platform (Shopify, WooCommerce, BigCommerce, etc.), monthly email list size, and whether you use SMS, I can narrow this down.

For an ecommerce brand, I’d focus on Klaviyo vs. Omnisend for your specific use case. Both support abandoned-cart flows, subject-line A/B testing, and revenue reporting.

• Klaviyo — strong fit if you want sophisticated segmentation and experimentation. You can A/B test subject lines inside flows, and its testing can use metrics such as placed-order rate. Klaviyo Help Center Klaviyo Help Center
• Omnisend — particularly straightforward for your exact workflow. Its abandoned-cart automation supports A/B splits, including subject lines, and its reporting shows sales/revenue attributed to each path. Omnisend Help Center Omnisend Help Center
• ActiveCampaign — also supports ecommerce revenue reporting and split testing, but its ecommerce attribution has specific rules: for example, campaign revenue is attributed when the recipient opens/clicks and then purchases within a seven-day window. ActiveCampaign Help Center ActiveCampaign

For your two requirements

If “easy A/B testing + revenue per campaign/variation” is the priority, I’d look closely at Omnisend. Its documentation explicitly shows sales revenue for each A/B-test path, while its campaign reports include revenue and revenue per message sent. Omnisend Help Center Omnisend Help Center

If you expect to need sophisticated segmentation, personalization, and more advanced lifecycle marketing later, Klaviyo is worth considering. It also specifically supports A/B testing subject lines within abandoned-cart flows. Klaviyo Help Center Klaviyo Help Center

If you tell me your ecommerce platform (Shopify/WooCommerce/etc.) and roughly how many emails you send per month, I can narrow this down based on the current pricing and integration differences.

For your specific use case—A/B testing abandoned-cart subject lines + seeing the revenue generated by each campaign/flow—I’d narrow it to Klaviyo and Omnisend.

• Klaviyo: Strong ecommerce-native analytics, abandoned-cart flows, and revenue attribution down to individual messages. Its own benchmark data also specifically supports A/B testing abandoned-cart timing, subject lines, copy, and imagery. Klaviyo Help Center Klaviyo
• Omnisend: Particularly straightforward for ecommerce. It supports subject-line A/B tests and lets you choose testing metrics, while its reporting shows revenue/sales performance for campaigns and automations. Omnisend Omnisend
• Mailchimp: It can A/B test subject lines and use revenue as a winning metric, but its ecommerce/automation analytics are generally less granular than the ecommerce-focused platforms above. Omnisend

The practical distinction: if your priority is deep revenue attribution and sophisticated customer segmentation, look closely at Klaviyo; if your priority is getting abandoned-cart testing and ecommerce reporting running simply, look closely at Omnisend.

One important detail: for abandoned-cart tests, I’d optimize for revenue per recipient / recovered revenue, not just open rate. Apple Mail privacy changes make opens a weaker decision metric, and revenue is ultimately the business outcome you care about. Salt Pot Digital

If you tell me Shopify/WooCommerce/another store, approximate monthly orders, and your email list size, I can narrow the choice based on the features and pricing that would actually matter for you.

For your specific use case—A/B testing abandoned-cart subject lines and seeing revenue per campaign without a lot of setup—the main platforms to look at are Klaviyo, Omnisend, and Mailchimp.

What the current feature sets show

• Omnisend supports A/B tests inside automations, including subject lines, and lets you evaluate the paths by sales/revenue. Its reports expose revenue, orders, and revenue per message sent for automations. Omnisend Help Center Omnisend Help Center
• Mailchimp supports subject-line A/B tests and can select a winner based on total revenue, not just opens or clicks. Its ecommerce attribution is based on the last message interaction before purchase. Mailchimp Mailchimp
• Klaviyo is particularly focused on ecommerce flows such as abandoned cart, and its own benchmarks specifically discuss A/B testing abandoned-cart subject lines, timing, copy, and other variables. Klaviyo

For your decision

I'd narrow it to Klaviyo vs. Omnisend if abandoned-cart optimization is the central requirement.

Omnisend has unusually direct reporting for the workflow: you can see revenue and revenue/message for an abandoned-cart automation and run an A/B split within that automation. Omnisend Help Center Omnisend Help Center

Klaviyo is worth considering if you expect to build a more sophisticated ecommerce lifecycle program beyond abandoned carts—multiple flows, behavioral segmentation, personalization, and systematic experimentation.

If you tell me your ecommerce platform (Shopify/WooCommerce/etc.), monthly orders, and approximate subscriber count, I can narrow down which of these fits your situation and what you'd likely pay.

If your two priorities are (1) A/B testing abandoned-cart subject lines and (2) easily seeing revenue attributed to each campaign/automation, I’d focus on ecommerce-native platforms rather than general-purpose email tools.

The strongest fits

• Omnisend — Its abandoned-cart automation supports A/B testing, including subject lines, and its reports show sales/revenue attributed to each automation path. It also lets you use sales as the success metric for appropriate automation tests. Omnisend Help Center Omnisend Help Center Omnisend

omnisend.com

• Mailchimp — Its A/B testing can test subject lines and, importantly for your use case, can automatically select a winner based on total revenue when your online store is connected. Mailchimp Mailchimp

mailchimp.com

What I'd look for specifically

For an abandoned-cart experiment, you ideally want:

Cart abandoned → randomly split A/B → different subject lines → measure opens/clicks → track orders and revenue by variant.

One nuance: for a subject-line test, open rate is logically the immediate test metric because the subject line affects whether someone opens. But I'd still want the platform to expose downstream revenue by variant, so you can make sure the subject line that gets more opens isn't ultimately producing fewer purchases.

If you tell me what ecommerce platform you're using (Shopify, WooCommerce, BigCommerce, etc.) and roughly how many contacts you have, I can narrow this down to the best fit and include pricing.

For the specific job you described—A/B testing abandoned-cart subject lines and seeing revenue generated per campaign—the current feature sets point most directly toward Klaviyo or Omnisend, with ActiveCampaign as another option if you want broader marketing automation.

• Omnisend: Its abandoned-cart automation supports A/B splits, including testing different email content/subject-line approaches, and its reporting shows sales revenue, revenue per placed order, and revenue per message sent. It also lets you adjust the sales-attribution window. Omnisend Help Center Omnisend Help Center Omnisend Help Center
• Klaviyo: Its ecommerce focus is particularly strong around abandoned-cart flows; Klaviyo publishes abandoned-cart performance benchmarks using revenue per recipient and explicitly recommends A/B testing variables including subject lines. Klaviyo
• ActiveCampaign: It supports abandoned-cart triggers through ecommerce integrations and provides campaign/automation revenue reporting, but its attribution has a fixed 7-day conversion period and requires the contact to open or click before revenue is attributed. ActiveCampaign Help Center ActiveCampaign Help Center

What I'd look at first

If your priority is “I want to quickly test subject line A vs. B and immediately see which one makes more money,” I'd investigate Omnisend first. Its documentation explicitly exposes revenue at the campaign/automation level and lets you compare A/B paths. Omnisend Help Center Omnisend Help Center

If you're building a more sophisticated ecommerce lifecycle program beyond abandoned carts—segmentation, customer profiles, multiple flows, etc.—Klaviyo is worth evaluating closely.

The biggest deciding factor is what ecommerce platform you're using (Shopify, WooCommerce, BigCommerce, etc.), because integrations and revenue attribution can materially change the experience.

For your specific needs — A/B testing abandoned cart subject lines and tracking revenue per campaign — you’ll want an ecommerce-focused platform rather than a general email sender.

The main options to consider:

My practical recommendation by situation

• If abandoned cart revenue is a major growth channel: look at Klaviyo. Its strength is tying customer behavior (viewed product, added cart, purchased, etc.) to automated flows and measuring revenue impact. Klaviyo Klaviyo Help Center
• If you want something easier to launch and manage: look at Omnisend. It is built around ecommerce workflows and includes A/B testing plus revenue reporting. Omnisend Omnisend
• If you’re early-stage and mostly sending newsletters/promotions: Mailchimp may be enough, but you may outgrow its ecommerce-focused features sooner. Omnisend

For abandoned carts specifically, I’d make sure whichever platform you choose can report:

• Revenue per recipient (RPR)
• Revenue per campaign/email
• Conversion rate from abandoned cart flow
• Winning A/B variant by revenue (not just opens)
• Customer-level attribution (which customers purchased after which email)

A key detail: don’t optimize only for subject-line open rate. A subject line that gets fewer opens can still win if it produces more purchases and revenue.

If you tell me your store platform (Shopify, WooCommerce, BigCommerce, etc.), monthly email volume, and approximate revenue/month, I can narrow this down further.

For abandoned-cart subject-line A/B testing + easy revenue tracking, I’d narrow it to Klaviyo and Omnisend.

Klaviyo provides campaign reporting that connects messages to website activity, checkouts, and directly attributable revenue. Its flow A/B testing can also test multiple variants, not just A/B. Klaviyo Help Center Klaviyo Help Center

Omnisend is particularly explicit about the workflow you're describing: its A/B testing supports subject lines, and automation reports show revenue, placed orders, revenue per placed order, and revenue per message sent. Its A/B automation splits can also use sales as the success metric. Omnisend Help Center Omnisend Help Center Omnisend Help Center

What I'd look for in your specific setup

If your workflow is:

Cart abandoned → Email #1 → test Subject A vs B → measure purchases/revenue

I'd make sure the platform lets you see revenue by variant, rather than merely open rate. That's important because a subject line can generate more opens without generating more purchases.

One nuance: for a pure subject-line test, open rate is the immediate metric being changed, but revenue is the business outcome you ultimately care about. Omnisend explicitly reports both A/B performance and attributed orders/revenue. Omnisend Help Center Omnisend Help Center

Bottom line: if you want the simplest ecommerce-focused setup, Omnisend has a particularly direct fit for these requirements. If you expect to build more sophisticated segmentation, analytics, and lifecycle automation, Klaviyo's deeper tooling may be worth the additional complexity. Klaviyo Help Center Klaviyo Academy

If you tell me your ecommerce platform (Shopify, WooCommerce, etc.) and roughly how many email subscribers you have, I can narrow this down to the better fit and explain the relevant pricing/feature differences.

For your specific use case—A/B testing abandoned-cart subject lines and seeing revenue attributed to each campaign/variation—I’d focus on Omnisend and Klaviyo.

Omnisend

Omnisend has a particularly direct workflow for what you described:

• Its abandoned-cart automation supports A/B testing, including subject lines. Omnisend Help Center Omnisend Help Center
• You can use sales/revenue as an A/B-test metric, and reports show revenue attributed to each automation path. Omnisend Help Center
• Campaign reports include revenue per campaign, per order, and per message sent. Omnisend Help Center
• Its automation editor displays sales/engagement data directly alongside workflow messages, which can make iteration pretty straightforward. Omnisend

omnisend.com

Klaviyo

Klaviyo is another strong fit, particularly if you expect your email program to become more sophisticated.

• Campaign A/B tests can test subject lines and use metrics such as open rate, click rate, or placed-order rate to determine a winner. Klaviyo Help Center
• Klaviyo's campaign analytics connect messages to website activity, checkouts, and directly attributable revenue. Klaviyo Help Center
• It has extensive ecommerce analytics and segmentation capabilities, which becomes useful as your marketing gets more complex.

klaviyo.com

My practical take

Budget pick: Omnisend is worth looking at first for this narrowly defined use case.

Upgrade pick: Klaviyo if you expect to eventually need more advanced segmentation, personalization, and customer lifecycle analytics.

One important nuance: for an abandoned-cart subject-line test, I'd make placed orders/revenue your ultimate business KPI, but also watch opens/clicks. Omnisend explicitly supports choosing sales as the success metric for appropriate A/B tests, while its documentation notes that subject-line tests primarily affect opens. Omnisend Help Center

If you tell me what ecommerce platform you're on (Shopify, WooCommerce, BigCommerce, etc.) and roughly how many email subscribers you have, I can narrow this down based on your likely cost and setup.

For your specific requirements—A/B testing abandoned-cart subject lines + easy revenue attribution—the two platforms I’d look at first are Klaviyo and Omnisend.

Klaviyo is particularly strong if your goal is to optimize for actual revenue rather than opens. Its A/B testing can use Placed Order Rate as the winning metric, and its campaign reporting directly attributes revenue and orders to individual messages. Klaviyo Help Center Klaviyo Help Center Klaviyo Help Center

Omnisend is attractive if you prioritize simplicity. It supports subject-line A/B tests and reports sales, orders, revenue per placed order, and revenue per message. Its automation reporting also supports revenue attribution for individual emails. However, its standard campaign A/B winner selection is based on open or click rate rather than purchase/revenue rate. Omnisend Help Center Omnisend

My practical take

If your main question is “Which subject line actually makes me more money?”, I'd investigate Klaviyo first because you can configure the experiment around a purchase-oriented metric rather than treating opens as the ultimate outcome. Klaviyo Help Center

If your priority is “I want something straightforward that gives me revenue reporting without a lot of complexity,” Omnisend is worth considering. Omnisend Help Center Omnisend

One important distinction: for an abandoned-cart automation, make sure you're testing the flow message rather than only sending one-off campaign tests. That's where the revenue attribution and automated cart recovery become especially useful.

If you tell me your ecommerce platform (Shopify, WooCommerce, etc.) and approximate monthly email revenue, I can narrow this down to the better fit and explain the relevant pricing/features.

For your specific use case — A/B testing abandoned cart subject lines + easily tracking revenue per campaign — I’d focus on ecommerce-first platforms rather than general email tools.

Here are the strongest fits:

My shortlist for your needs

1. Klaviyo — best if revenue optimization is the priority

• Built specifically around ecommerce customer data.
• Lets you see whether a subject line change actually produces more purchases, not just higher opens.
• Good if you plan to optimize:
  • abandoned cart sequences
  • welcome flows
  • post-purchase upsells
  • customer segments
  • VIP/lapsed buyer campaigns

www.klaviyo.com

2. Omnisend — best if you want faster setup and simpler workflows

• Strong Shopify/ecommerce focus.
• Easier learning curve for many small-to-mid-sized stores.
• Supports abandoned cart automations and A/B testing of email elements. www.omnisend.com

What I would look for specifically

Before choosing, make sure the platform can report:

• Revenue per recipient (RPR) — better than open rate for cart recovery
• Revenue per campaign
• Revenue per flow/email step
• Conversion rate after click
• A/B test winner based on revenue, not only opens

For abandoned carts, I would avoid optimizing purely for open rate. A subject line that gets fewer opens but more purchases is usually the winner.

If you tell me:

1. your ecommerce platform (Shopify, WooCommerce, Magento, etc.),
2. monthly email sends or list size, and
3. approximate revenue/month,

I can narrow it down between Klaviyo vs Omnisend vs alternatives.

For your specific use case—A/B testing abandoned-cart subject lines and seeing revenue attributed to each campaign/variation—I’d narrow it to Klaviyo and Omnisend.

The practical choice

If your priority is simplicity: Omnisend is particularly well aligned with what you're describing. Its automation A/B testing lets you split an abandoned-cart workflow and compare the paths, with sales/revenue shown for each path. Its reports also expose revenue at the campaign and individual-message level. Omnisend Help Center Omnisend Help Center Omnisend Help Center

omnisend.com

If you expect to build a more sophisticated lifecycle-marketing program: Klaviyo has deeper testing and analytics capabilities. It supports subject-line testing directly within flows and campaign/flow reporting around placed orders and attributable revenue. Klaviyo Help Center Klaviyo Help Center Klaviyo Help Center

klaviyo.com

One important nuance: for an abandoned-cart subject-line test, don't judge the winner purely by open rate. Apple Mail privacy changes make opens less reliable; ultimately I'd watch recovered revenue / placed orders per recipient, while using opens and clicks as diagnostic metrics. Omnisend itself recommends clicks as the winning metric for iOS-heavy audiences. Omnisend Help Center

If you tell me your ecommerce platform (Shopify, WooCommerce, etc.) and roughly how many email subscribers you have, I can narrow this down further based on setup, pricing, and attribution.

For your specific use case—A/B testing abandoned-cart subject lines and easily seeing revenue generated—I’d narrow it to Klaviyo vs. Omnisend.

Klaviyo lets you A/B test subject lines and choose testing metrics, including placed-order rate. Its reporting also exposes revenue attributed to individual messages, and you can export A/B-test variation data. help.klaviyo.com

Omnisend is particularly straightforward for this exact workflow. Its abandoned-cart automation supports A/B testing, including subject lines, and its reporting shows revenue per campaign, per order, and per message, as well as revenue generated by abandoned-cart automations. support.omnisend.comsupport.omnisend.com

My practical take

• Choose Omnisend if your priority is “I want to set up abandoned-cart tests quickly and immediately understand which emails make money.” Its reporting and A/B-testing workflow map very closely to what you're asking for. support.omnisend.comsupport.omnisend.com
• Choose Klaviyo if you expect to build a more sophisticated lifecycle/CRM program over time—segmentation, flows, attribution, SMS, behavioral analytics, etc. Klaviyo also supports revenue attribution and deeper campaign/flow analytics. help.klaviyo.com

If abandoned-cart subject-line testing + revenue tracking are the two deciding factors, I'd start with Omnisend. It has a particularly clean fit for that job.

If you tell me your ecommerce platform (Shopify/WooCommerce/etc.), monthly email volume, and approximate subscriber count, I can also check the current 2026 pricing and tell you which is likely to be cheaper for your store.

For your specific use case—A/B testing abandoned-cart subject lines and seeing revenue tied to each campaign/variant—the two platforms I’d look at first are Klaviyo and Omnisend.

The key distinction

Klaviyo lets you A/B test subject lines and select a winning metric such as open rate, click rate, or placed-order rate. Its reporting also connects messages to website activity, checkouts, and attributable revenue. Klaviyo Help Center Klaviyo Help Center Klaviyo Help Center

klaviyo.com

Omnisend is particularly explicit about the workflow you're describing: its abandoned-cart automation supports A/B testing subject lines, and its reports show sales/revenue by automation and message. Its automation A/B tests can compare sales revenue between paths. Omnisend Help Center Omnisend Help Center Omnisend Help Center

omnisend.com

What I'd focus on

If your priority is deep ecommerce analytics and sophisticated experimentation, investigate Klaviyo.

If your priority is "I want to set up abandoned-cart tests quickly and see the resulting revenue without a lot of complexity," investigate Omnisend.

One important nuance: for a subject-line test, don't judge the winner solely by revenue. Subject lines primarily affect opens; ideally, track placed orders/revenue downstream while also watching open rate, because a subject line that gets more opens isn't necessarily the one that generates more purchases. Omnisend itself recommends matching the winning metric to what you're testing. Omnisend Help Center

If you tell me your ecommerce platform (Shopify, WooCommerce, BigCommerce, etc.) and roughly how many orders/month you have, I can narrow this down to the better fit and include the current pricing.

If your priorities are specifically A/B testing abandoned-cart subject lines and seeing revenue attributed to each campaign/variant, I’d narrow it to Klaviyo, Omnisend, and ActiveCampaign.

The practical distinction

Klaviyo gives you a particularly direct setup for your use case. Its flow A/B testing supports subject-line tests, and its reporting can attribute placed orders/revenue to messages. help.klaviyo.com

Omnisend is also very close to exactly what you're asking for: its abandoned-cart automation supports A/B testing, and the automation statistics explicitly show sales/revenue attributed to each test path. support.omnisend.com Its campaign A/B reports also include revenue and show revenue for each variation. help.klaviyo.comsupport.omnisend.comhelp.activecampaign.com

ActiveCampaign has the broadest split-testing capability of these three, including up to five variations and multiple success metrics, plus dedicated attribution functionality. www.activecampaign.com It also supports abandoned-cart triggers through Shopify, WooCommerce, Magento, and other integrations. help.activecampaign.com

For your exact workflow, the key thing I'd verify before buying is how each platform calculates attributed revenue—especially the attribution window. Omnisend, for example, explicitly lets you configure its sales-attribution window. support.omnisend.com

If you tell me what ecommerce platform you're using (Shopify, WooCommerce, etc.) and roughly how many contacts/orders you have per month, I can narrow down which one fits your setup and likely cost.

For your specific use case—A/B testing abandoned-cart subject lines and easily tying emails to revenue—I’d focus on Klaviyo and Omnisend rather than a general-purpose email platform.

Klaviyo

Klaviyo is particularly built around ecommerce. Its A/B testing supports subject lines and can use placed-order rate as a winning metric when the account has that metric available. It also supports A/B testing emails inside flows, which is directly relevant to abandoned-cart sequences. help.klaviyo.com

Omnisend

Omnisend is also a very direct fit. Its abandoned-cart automation has built-in A/B testing, and its reports explicitly show revenue per campaign, order, and message, as well as revenue generated by abandoned-cart automations. support.omnisend.com

One especially useful detail: Omnisend lets you test two subject lines and can report revenue for each variation, rather than forcing you to judge the test purely by opens/clicks. help.klaviyo.comsupport.omnisend.comsupport.omnisend.com

Mailchimp

Mailchimp supports subject-line A/B testing and can use total revenue as the winner metric. Its ecommerce attribution uses a last-touch model. mailchimp.com

My practical takeaway

If you're running an ecommerce store and your priority is:

“I want to test Your cart is waiting 👀 vs. Still thinking it over? and quickly see which one actually generated more sales.”

I'd look most closely at Klaviyo vs. Omnisend.

• Choose Klaviyo if you expect to build sophisticated segmentation, lifecycle marketing, and increasingly complex flows.
• Choose Omnisend if you prioritize a simpler ecommerce-focused workflow and very straightforward campaign/automation revenue reporting.

If you tell me what ecommerce platform you're using (Shopify, WooCommerce, etc.) and roughly how many emails you send/month, I can narrow down which one makes more sense for your setup and cost.

For your specific use case—A/B testing abandoned-cart subject lines and easily seeing revenue attributed to each campaign—the two platforms I’d put at the top of your shortlist are Klaviyo and Omnisend.

The key distinction

If your priority is “I want sophisticated customer data, segmentation, attribution, and testing that I can eventually build a serious lifecycle-marketing program around,” Klaviyo has a very deep feature set. Its A/B testing supports subject lines in flows, and its reporting connects messages to placed orders and attributed revenue. academy.klaviyo.comhelp.klaviyo.com

If your priority is “I want to set up abandoned-cart tests quickly and see which version actually generated sales without a lot of complexity,” Omnisend is particularly aligned with that workflow. Its automation A/B testing explicitly reports Sales/revenue for each test path, while its campaign reporting includes revenue attribution. support.omnisend.comsupport.omnisend.com

One subtle point: don't judge an abandoned-cart subject-line test purely by open rate. Apple Mail privacy features make opens less reliable. For the business outcome, I'd ultimately track revenue per recipient (RPR), conversion/placed-order rate, and total attributed revenue, while using opens as a secondary diagnostic. Klaviyo specifically supports placed-order rate as an A/B-test metric in applicable tests, while Omnisend reports revenue for automation test paths. support.omnisend.comsupport.omnisend.comhelp.klaviyo.com

Bottom line: If you tell me what ecommerce platform you're using (Shopify, WooCommerce, BigCommerce, etc.), roughly how many contacts you have, and your monthly email volume, I can compare the current pricing/features for Klaviyo vs. Omnisend specifically for your store.

For your specific use case—A/B-testing abandoned-cart subject lines and seeing revenue attributable to each campaign—the strongest options to evaluate are Omnisend and Klaviyo.

If simplicity is your priority: Omnisend

Omnisend explicitly supports A/B testing inside abandoned-cart automations, including testing subject lines based on which variation generates more sales. Its reporting breaks down revenue for the A/B variants, and its campaign reporting includes revenue attributed to each campaign. support.omnisend.comacademy.klaviyo.comhelp.klaviyo.comdocs.customer.iosupport.omnisend.com

It also has dedicated ecommerce revenue attribution, with configurable attribution windows. support.omnisend.com

Omnisend

If you want the deeper ecommerce analytics: Klaviyo

Klaviyo is particularly strong if you expect your email program to become more sophisticated. It supports A/B testing subject lines within flows, including abandoned-cart flows, and provides revenue-per-recipient metrics for evaluating flow performance. academy.klaviyo.com

Its abandoned-cart tooling also gives you considerably more targeting/customization than the basic ecommerce-platform flows. help.klaviyo.com

Klaviyo

My decision rule

• Small/medium ecommerce store + “I want this to be easy” → Omnisend
• Growing ecommerce brand + sophisticated segmentation/analytics → Klaviyo
• Highly customized product/customer journeys beyond typical ecommerce → Customer.io; its current analytics support people-based revenue attribution and statistical A/B-test analysis. docs.customer.io

One important nuance: don't optimize the abandoned-cart subject-line test purely for open rate. If your real goal is revenue, I'd structure the test so the ultimate comparison is revenue per recipient / conversion, while using opens and clicks as diagnostic metrics. Omnisend, for example, reports revenue for the individual A/B variants. support.omnisend.comacademy.klaviyo.comhelp.klaviyo.comdocs.customer.iosupport.omnisend.com

If you tell me your ecommerce platform (Shopify, WooCommerce, etc.) and roughly how many emails/orders you get per month, I can narrow this down to the better fit and compare the current pricing.

For your specific use case — A/B testing abandoned cart subject lines + easily tracking revenue per campaign — you’ll want an ecommerce-focused platform rather than a general newsletter tool.

A practical shortlist:

My decision framework

Choose Klaviyo if:

• You care about maximizing abandoned-cart revenue over time
• You want advanced segments (VIP customers, high cart value, repeat buyers, product interest)
• You expect email to become a major revenue channel
• You want deeper testing beyond subject lines (send timing, offers, flow branches) www.klaviyo.com

Choose Omnisend if:

• You want a faster setup
• You primarily run Shopify/ecommerce automations
• You want solid testing and revenue reporting without as much complexity www.omnisend.comsupport.omnisend.com

Avoid choosing based only on open rates. For abandoned cart emails, the metric that matters most is usually:

• Revenue per recipient
• Recovered cart revenue
• Conversion rate
• Profit after discounts

A subject line that gets fewer opens but more purchases is the winner.

For your exact workflow, I’d set up:

1. Abandoned cart flow:
   • Email 1: 1–3 hours after abandonment
   • Email 2: 24 hours later
   • Email 3: 48–72 hours later (possibly with incentive)

2. A/B tests:
   • Subject line A: urgency (“Your cart is waiting”)
   • Subject line B: curiosity (“Still thinking about these?”)
   • Then test incentives, timing, and number of emails

3. Dashboard metrics:
   • Revenue per recipient
   • Revenue per campaign
   • Cart recovery rate
   • Conversion rate by variant

If you’re on Shopify, I’d narrow the choice to Klaviyo vs. Omnisend. If you tell me your store platform (Shopify/WooCommerce/custom), monthly email volume, and approximate revenue, I can help pick between those two.

For your specific use case—A/B testing abandoned-cart subject lines and seeing revenue per campaign without a lot of setup—the two strongest fits are Klaviyo and Omnisend.

If revenue attribution is your #1 priority

Klaviyo has particularly good revenue analytics. It explicitly supports revenue per recipient (RPR) for flows, including abandoned-cart emails, and recommends A/B testing subject lines and other flow variables to improve it. help.klaviyo.com

Klaviyo

If you want the easiest implementation

Omnisend is very well aligned with exactly what you described. Its abandoned-cart automation supports A/B testing, including different subject lines, and its reports show revenue attributed to each campaign and automation. Its A/B-test reports also break out revenue for each variation. support.omnisend.com

Omnisend

My practical takeaway: if you're primarily an ecommerce store and want to get abandoned-cart subject-line tests running quickly, Omnisend is likely the simpler choice. If you expect to build sophisticated segmentation, lifecycle flows, and deeper revenue analysis over time, Klaviyo gives you more analytical depth.

One important nuance: for a subject-line test, I'd judge the winner primarily on revenue/conversion, not just open rate. A subject line that gets more opens but fewer purchases isn't necessarily the better subject line. Omnisend lets you see revenue for the A/B variations, while Klaviyo provides RPR for flow analysis. help.klaviyo.comsupport.omnisend.com

If you tell me what ecommerce platform you use (Shopify, WooCommerce, etc.) and roughly how many orders/month you have, I can narrow this down based on integration, pricing, and how much revenue attribution you'll actually get.

For your specific use case—A/B testing abandoned-cart subject lines + easily seeing revenue attributed to campaigns—the main options worth comparing are Klaviyo, Omnisend, and Mailchimp.

Klaviyo: Its A/B testing supports subject lines, and its reporting can show revenue directly attributable to individual messages. It also supports A/B testing within flows, which is particularly relevant for abandoned-cart emails. help.klaviyo.com

Omnisend: Its abandoned-cart automation specifically supports A/B testing, including testing different subject lines to determine which generates more sales. Its reports show revenue for campaigns and automation, and it supports configurable sales attribution. support.omnisend.com

Mailchimp: You can A/B test subject lines and choose total revenue as the metric for determining a winner, while its abandoned-cart reporting includes recovered checkouts and products sold. mailchimp.com

The practical distinction

If your priority is “I want to set up abandoned-cart tests and immediately understand which version makes more money,” Omnisend is particularly straightforward: its documentation explicitly describes testing abandoned-cart subject lines based on revenue and provides revenue attribution in campaign/automation reporting. support.omnisend.com

If you expect to build a more sophisticated ecommerce lifecycle program—segmentation, multiple flows, deeper attribution, email/SMS, etc.—Klaviyo has substantially more analytics depth. help.klaviyo.com

One important nuance: don't optimize abandoned-cart subject lines purely for open rate. The business outcome is recovered revenue. Omnisend can report revenue by A/B variation, while Klaviyo's flow testing supports conversion-oriented metrics in addition to engagement metrics. help.klaviyo.comsupport.omnisend.com

If you tell me your ecommerce platform (Shopify, WooCommerce, BigCommerce, etc.) and roughly how many email subscribers you have, I can compare the current pricing and exact setup for these three.

For your specific use case—A/B testing abandoned-cart subject lines and easily seeing revenue attributed to each campaign/variation—the strongest fits are Omnisend and Klaviyo.

Why I'd shortlist Omnisend

Omnisend lets you put an A/B Test Split directly inside an abandoned-cart automation, testing subject lines and comparing the resulting paths by opens, clicks, or sales revenue. Its automation reports show attributed revenue for each path. support.omnisend.com

It also has a dedicated campaign report showing revenue attributed to the campaign, and you can configure its sales-attribution window. support.omnisend.com

Omnisend

When I'd choose Klaviyo instead

Klaviyo is worth considering if you expect to eventually want more sophisticated segmentation, lifecycle marketing, personalization, and analytics. It supports A/B testing subject lines in flows and campaigns, and campaign tests can use metrics such as open rate, click rate, and placed-order rate. help.klaviyo.com

Klaviyo

Bottom line: If your priority is “I want to set up abandoned-cart tests quickly and clearly see which version makes more money,” Omnisend is the simpler fit. If you're building a more sophisticated ecommerce CRM/marketing stack, Klaviyo is the broader platform.

One important nuance: for subject lines, don't optimize solely for opens. Apple Mail privacy makes open rates less reliable; ultimately, I'd track revenue per recipient / placed-order rate alongside opens. Omnisend specifically recommends sales as the success metric for tests where the content affects purchasing behavior. support.omnisend.comsupport.omnisend.com

For your specific use case—A/B testing abandoned-cart subject lines + seeing revenue attributed to each campaign/variation—I’d narrow it to Klaviyo vs. Omnisend.

My practical take

Choose Klaviyo if email is going to become a major part of your ecommerce growth stack. Its reporting goes beyond basic campaign revenue into customer, segment, and flow analytics, and it supports A/B testing subject lines directly inside flows. help.klaviyo.com

Choose Omnisend if your priority is “I want to set up abandoned-cart testing and immediately see which version makes money” with less complexity. Its current A/B testing explicitly supports subject lines in automations, and the results include sales/revenue by path. support.omnisend.comsupport.omnisend.com

One important nuance: don't optimize an abandoned-cart subject-line test purely for opens. If your ultimate objective is revenue, you should eventually compare downstream placed orders/revenue as well. Omnisend explicitly lets automation A/B tests evaluate sales, while Klaviyo provides revenue attribution at the message/campaign level. help.klaviyo.comsupport.omnisend.com

If you tell me your ecommerce platform (Shopify, WooCommerce, BigCommerce, etc.) and roughly how many contacts you have, I can compare the current pricing and the exact setup I'd use for the abandoned-cart test.

For your specific use case—A/B testing abandoned-cart subject lines and seeing revenue attributed to each campaign/variant—I’d narrow it to Klaviyo, Omnisend, and Drip.

How I'd choose

Klaviyo — best if you want sophisticated ecommerce analytics and segmentation. Its A/B testing supports subject lines, content, and send times, and campaign analytics include placed orders and revenue. help.klaviyo.com

Omnisend — particularly compelling if your priority is “set up the test quickly and see which version actually generated sales.” Its automation A/B tests can compare subject lines and other elements, while reports show sales/revenue for each path. It also supports campaign-level revenue reporting. support.omnisend.com

Drip — a good fit if you want straightforward testing. You can test up to four subject-line/content variations and see opens, clicks, and revenue for each variation on the campaign dashboard. Its revenue attribution window is also configurable. help.drip.comsupport.omnisend.com

My practical takeaway

If your requirement is specifically:

“I want to test abandoned-cart subject line A vs. B and immediately know which one made more money.”

Omnisend is probably the simplest fit. It explicitly supports A/B testing within automations and lets you compare sales revenue between the paths. support.omnisend.com

If you're building a more sophisticated ecommerce marketing operation where segmentation, customer data, and analytics will become increasingly important, Klaviyo is worth considering.

One important nuance: don't optimize an abandoned-cart subject-line test purely for open rate. The subject line primarily affects opens; ultimately, you want to watch revenue per recipient / placed-order rate as the downstream business metric. Apple's privacy changes also make opens a less reliable metric. help.drip.comsupport.omnisend.com

If you tell me what ecommerce platform you're using (Shopify, WooCommerce, etc.) and roughly how many contacts you have, I can compare the current pricing and features of Klaviyo vs. Omnisend vs. Drip for your situation.

For your specific use case—A/B testing abandoned-cart subject lines + easily seeing revenue attributed to each campaign—I’d narrow it to Klaviyo vs. Omnisend.

My take

Choose Omnisend if your priority is “easy.” Its A/B testing lets you test subject lines and its reports explicitly show revenue for the campaign and each A/B version. Its abandoned-cart automation also supports A/B tests where sales/revenue can be the success metric. support.omnisend.com

Choose Klaviyo if you expect your marketing to become more sophisticated. It supports A/B testing of flow subject lines, and its campaign analytics include revenue and placed orders, with A/B-test variations available in exports. help.klaviyo.com

One important nuance: for a pure subject-line test, I'd optimize for opens/clicks rather than revenue, because the subject line primarily affects whether someone opens the email. Then evaluate whether the winning subject line ultimately produces more orders/revenue. Omnisend explicitly distinguishes these metrics in its testing guidance. support.omnisend.comsupport.omnisend.com

Bottom line: If you're a typical Shopify/ecommerce store and want the least friction, Omnisend is probably the simpler fit. If you're building a more sophisticated lifecycle-marketing operation, Klaviyo gives you more room to grow.