Every Klaviyo dashboard prominently displays revenue figures: total revenue attributed to email, revenue per flow, revenue per campaign. These numbers look impressive and feel validating. But how accurate are they? And what do they really mean for your business?
Revenue attribution is one of the most misunderstood aspects of email marketing. This guide explains exactly how Klaviyo measures revenue, where the numbers can mislead, and how to interpret your data accurately. We deal with attribution questions regularly through our Klaviyo email marketing services.
What is revenue attribution?
Revenue attribution is the process of connecting a purchase to the marketing activity that influenced it. When a customer buys a product, attribution answers the question: which email, SMS, ad, or other touchpoint drove this sale?
In a perfect world, we could trace every purchase to a single cause. In reality, a customer might see a Facebook ad, browse your site, receive an abandoned cart email, click through, and then purchase two days later. Multiple touchpoints contributed. Attribution models are imperfect attempts to assign credit.
Why it matters
Attribution data drives budget allocation. If Klaviyo shows that email generates 35 per cent of your revenue, that justifies continued investment in email. If a specific flow shows high revenue, that validates the time spent optimising it. Inaccurate attribution leads to poor investment decisions.
How Klaviyo attribution works
Klaviyo uses a last-touch attribution model with a configurable time window. Here is the process:
- Klaviyo sends an email or SMS to a customer
- The customer opens or clicks the message
- Within the attribution window (default: 5 days), the customer makes a purchase
- Klaviyo attributes the purchase revenue to that email or SMS
Open attribution vs click attribution
Klaviyo can attribute revenue based on either opens or clicks. If a customer opens an email (but does not click) and purchases within the window, the revenue can be attributed to the email. If they click and purchase, it is also attributed.
Click attribution is more conservative and more accurate. Open attribution is generous and can overstate email's impact because Apple Mail Protection and other privacy features automatically open emails without user interaction.
Attribution windows explained
The attribution window is the time period after an email interaction during which purchases are attributed to that email. Klaviyo's default is 5 days for both opens and clicks.
| Window | Effect | Best for |
|---|---|---|
| 1 day | Very conservative, attributes only immediate purchases | Brands wanting strict attribution |
| 3 days | Moderate, captures most email-influenced purchases | General use |
| 5 days (default) | Generous, captures delayed purchase decisions | Products with longer consideration periods |
| 7 days | Very generous, may overstate email impact | High-value products with long sales cycles |
Shorter windows give more conservative (and arguably more accurate) numbers. Longer windows give higher revenue numbers but include more purchases that might have happened regardless of the email.
Flow vs campaign attribution
Understanding the difference between flow and campaign attribution is essential for accurate reporting.
Flow attribution
Flows are behaviour-triggered. An abandoned cart email is sent because the customer abandoned their cart. When that customer purchases, there is a strong causal link between the email and the purchase. Flow attribution tends to be more accurate because the email was directly relevant to the customer's current intent.
Campaign attribution
Campaigns are sent on a schedule to a list or segment. If you send a promotional campaign and a customer on that list happens to purchase the next day, the revenue is attributed to the campaign — even if the customer was going to buy anyway. Campaign attribution is inherently noisier.
The healthy split
A well-optimised Klaviyo account typically generates 40 to 60 per cent of email revenue from flows and 40 to 60 per cent from campaigns. If campaigns dominate heavily, it may indicate that the flow revenue is being undercounted or that flows are underoptimised.
The over-counting problem
The biggest limitation of Klaviyo's attribution model is over-counting. If a customer opens a campaign email on Monday, clicks an abandoned cart email on Tuesday, and purchases on Wednesday, Klaviyo attributes the revenue to both emails. The sum of email-attributed revenue exceeds the actual purchase value.
Why this happens
Klaviyo evaluates each email independently. Each email asks: did the customer engage with me and then purchase within my window? If yes, I get credit. There is no deduplication across emails.
How to account for it
- Do not sum flow revenue and campaign revenue and treat it as your total email revenue
- Use Klaviyo's overview dashboard which provides a deduplicated total
- Cross-reference Klaviyo revenue with your Shopify revenue to calculate the realistic email contribution
- Focus on trends rather than absolute numbers — is email revenue growing month over month?
Attribution best practices
1. Use click-based attribution for decisions
Open-based attribution is unreliable due to privacy features. When evaluating email performance, focus on click-attributed revenue. This is more conservative but more accurate.
2. Keep your attribution window consistent
Pick an attribution window and stick with it. Changing the window makes historical comparisons meaningless. We recommend 3 to 5 days for most ecommerce brands.
3. Benchmark email as a percentage of total revenue
Track what percentage of your total Shopify revenue is attributed to Klaviyo. This percentage should be 25 to 40 per cent for a well-run email programme. Track this monthly to identify trends. For more on analytics, see our ecommerce analytics guide.
4. Do not over-optimise for attribution
Do not send more emails just to capture more attributed revenue. The goal is to send the right emails to the right people at the right time. If you increase send volume but annoy customers, you might see higher attributed revenue but lower total business revenue.
5. Look at incremental revenue, not just attributed revenue
The true test of an email's value is whether it generated revenue that would not have happened without it. Run holdout tests (suppress a small group from receiving an email and compare their purchase rate to the group that received it) to measure true incremental impact.
Comparing attribution across platforms
Every marketing platform reports revenue differently. Klaviyo, Google Analytics, Facebook Ads, and Shopify all use different attribution models. This means the sum of revenue reported across all platforms will always exceed your actual total revenue.
This is normal and expected. Each platform is answering a different question. Klaviyo asks: did the customer engage with an email before purchasing? Google Ads asks: did the customer click an ad before purchasing? Both can be true for the same purchase.
Use each platform's attribution for internal benchmarking within that channel, but use your Shopify dashboard as the single source of truth for total revenue.
Klaviyo's revenue attribution is a useful tool for measuring email performance and making investment decisions. But it is not perfect, and treating the numbers as absolute truth will lead to poor decisions. Understand the limitations, use the data directionally, and benchmark against your total business revenue for the most accurate picture.
If you want help interpreting your Klaviyo data or setting up a reliable reporting framework, get in touch. We provide monthly performance reporting as part of our Klaviyo email marketing services.
