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Ecommerce Analytics · focused work

Ecommerce attribution reporting

Every advertising platform reports the sales it believes it caused, and adding those reports together produces more revenue than the store actually took. Attribution reporting is the work of building one view the business argues from, deciding which number answers which question, and testing the claims that carry enough budget to be worth testing.

This is the right work if

  • Adding up the conversions each platform claims produces more orders than the store received
  • Budget discussions run on different numbers depending on who prepared the slide
  • Nobody has agreed which system is the authority on revenue
  • Lookback windows differ across platforms and no report accounts for the difference
  • New customer revenue is not separated from repeat revenue anywhere

What it is

The three views and what each is for

The store's own order data is the fixed total. It is the only number that is not a model, and it is the denominator everything else is compared against. Platform reported conversions describe what each channel claims using its own lookback window, its own rules about which interactions count and its own modelling for the gaps. A cross-channel analytics model gives one consistent set of rules across every channel, which makes channels comparable to each other while agreeing with none of them. None of the three is correct in isolation, and the mistake most stores make is choosing one and treating the others as errors.

The reporting work defines which view is used for which decision, aligns windows and definitions so differences stop being mysterious, and builds a report that shows all three next to spend. Around that sit the measures that do not depend on tracking at all: blended efficiency across total revenue and total marketing cost, contribution margin after advertising, the split between first orders and repeat orders, a self-reported question after checkout, and holdout tests for the channels large enough to justify one. The output is not a perfect model. It is a small set of numbers, an agreed cadence, and a rule for what each one triggers.

How it is done

The work, in order

What changes

  • The business plans from one report instead of several conflicting ones
  • Every claimed figure sits beside the store's own revenue total
  • Acquisition cost is measured against new customers rather than all orders
  • Channel weight is corrected by tests instead of by self-reporting
  1. Fix the total before anything else

    Take the store's own orders, net of cancellations and refunds, as the authority on revenue for the period. Every channel claim is then expressed as a share of a known total rather than as a free-standing figure nobody can place.

  2. Document each platform's rules

    Record the lookback window, the interaction types counted and the modelling each platform applies, and put that summary at the top of the report. Most arguments about attribution end quickly once everyone can see that two numbers were measuring different things.

  3. Build one report with all three views

    Weekly, showing store revenue, platform-claimed conversions, the analytics model, spend per channel, and blended efficiency for the business as a whole. Same definitions, same period boundaries and the same currency treatment every week.

  4. Separate first orders from repeat

    Split revenue and orders by whether the customer had bought before, so acquisition spend is measured against acquisitions. A channel that looks efficient on total revenue can be selling almost entirely to existing customers, which is a different business decision.

  5. Ask the customer at checkout

    Add a short question about how they first heard of the store. The answers are imprecise and directionally useful, and they are the only visibility most stores get into podcasts, word of mouth, print and anything else that leaves no click behind.

  6. Test the channels worth testing

    For the largest spend, run a geographic holdout or a scheduled pause long enough to cover the store's normal purchase cycle, then compare total revenue rather than campaign revenue. Use what the test shows to adjust how much weight the routine reports carry.

Questions

Attribution reporting questions

By CartKernel · Last reviewed

Which number should the business treat as the truth?

The store's own revenue for totals, and the analytics model for comparing channels against each other, with platform figures used to manage inside each platform. Naming the role of each one, in writing, prevents most of the disagreement that attribution debates are actually about.

Is a data-driven model better than last click?

It usually distributes credit more sensibly across a longer journey, and it is harder to explain and impossible to audit. Many stores run both, using the modelled view for planning and last click as a stable reference that behaves predictably when the modelled view moves for reasons nobody can see.

Are post-purchase survey answers reliable enough to use?

Not as precise numbers, and yes as a directional signal. People misremember and skip the question, so treat the results as trends over time rather than percentages of truth. Their real value is revealing channels no tracking captures, which no amount of tagging work would have surfaced.

How often should the attribution setup be reviewed?

The report runs weekly, and the underlying assumptions deserve a review each quarter or after any platform changes its measurement. Windows, models and consent behaviour all shift, and a report built on last year's rules will keep producing confident numbers that quietly stopped being comparable.

Can better tracking solve attribution on its own?

No. Tracking improves the data available; it cannot tell you what would have happened without the ad, which is the actual question behind every budget decision. That answer only comes from holding a channel back and measuring the difference, which is why testing sits inside this work rather than beside it.

Related work and answers

Ecommerce AnalyticsGA4 ecommerce trackingGA4 ecommerce tracking: the full event set with a complete items array, purchases that fire once, session continuity, and a reconciliation you can explain.OpenEcommerce AnalyticsServer-side tagging for ecommerceServer-side tagging for ecommerce: a first-party collection endpoint, orders sent from the store's own backend, deduplication, and one place to govern data.OpenGoogle AdsBrand search campaigns for ecommerceBrand search campaigns for ecommerce: defending the store name, matching landing pages to modifiers, and testing how much of the spend is incremental.OpenGoogle AdsEcommerce remarketing campaignsEcommerce remarketing campaigns: lists built from real behaviour, windows set from the buying cycle, exclusions, and a message per distance from purchase.OpenAnswerWhich attribution model should an ecommerce store use?No attribution model is correct. Use one consistently for reporting, platform data for bidding, and holdout tests for budget. How to build that stack.OpenAnswerHow do you measure incrementality for ecommerce ads?Incrementality is measured by withholding advertising and comparing, not by attribution. The test designs that work for a store and how to size them.OpenAnswerHow do you track new versus returning customer revenue?Track new versus returning revenue from the order record, not from analytics sessions. How to define a new customer and the joins that break the split.OpenAnswerIs Looker Studio enough for ecommerce reporting?Looker Studio is enough for most stores as a presentation layer. Where it strains, when a warehouse earns its place, and how to build a report people read.Open

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