Klaviyo defaults to last-click attribution for all conversions tracked through its platform. If someone clicks an email link and purchases within the attribution window, that email gets full credit for the sale. The standard attribution window is 5 days for email clicks and 1 day for email opens, though you can adjust these in account settings. This matters because ecommerce journeys are rarely linear. A customer might see a welcome email, browse your site from Google two days later, get a browse-abandonment email, ignore it, then convert from a promotional email a week later. Under last-click, only that final promotional email shows revenue in your Klaviyo dashboard. The earlier touchpoints contributed zero attributed revenue, even though they warmed the lead. Klaviyo does offer first-touch and linear models in the attribution report under Analytics, but these are view-only. Your flow performance metrics, campaign ROI calculations, and automated benchmarking all use last-click. For most DTC brands, this inflates the apparent value of discount-heavy broadcasts and undervalues educational sequences or first-touch automations. We see this clearly when running multi-channel attribution audits for Ottawa ecommerce clients. A flow might show 4x ROI in Klaviyo but contribute far more when you account for assists. GA4 uses data-driven attribution by default, so revenue numbers between platforms rarely match. Klaviyo will typically report higher email revenue because it claims last-click credit even when someone landed via paid search. Practical implications: Don't kill a welcome series just because Klaviyo shows low attributed revenue. Check open rates, click rates, and engagement over time. For larger brands (500k+ emails/month), consider exporting raw event data to a warehouse and running custom multi-touch models. For most brands under that threshold, accept that last-click is directionally useful but systematically undervalues top-of-funnel content. Adjust attribution windows to match your actual sales cycle, especially if you sell considered purchases over CAD 200 where the decision timeline stretches beyond five days.