How often to check marketing attribution: once a quarter

Check your marketing attribution once a quarter, before the next quarter's budget is set, and again after a tracking or site change, when you add or cut a channel, before peak season, and whenever a platform's ROAS and your revenue disagree. The quarterly check catches the silent problems, like a theme update in week three that stopped sending purchases to GA4. The event checks catch the ones you can see coming.

Think of it as a dental checkup. Most visits find nothing, and you book them anyway, because the problems worth catching do not hurt until they are expensive.

What is an attribution audit?

An attribution audit is a check that the numbers you set budgets on still measure what you think they measure. It works through four questions in order: are purchases still recorded, do visits still arrive with their source, do the platforms' claims add up to more than you sold, and do the channels you pay for still cause sales.

A one-off audit happens when something already looks wrong. A checkup is the same audit on a calendar, so a broken tag is found in the quarter it broke, not two quarters later in a budget meeting.

How often should an ecommerce brand audit its marketing attribution?

Once a quarter as a routine, and out of turn when one of four things happens. In a normal quarter none of this is urgent, and that is the point: the routine is cheap because nothing is on fire.

Why a quarter is the interval:

1. Budgets are set by quarter. A check belongs before the decision it feeds. Run after the budget meeting, it only explains the mistake.
2. The channel mix drifts. An affiliate grows, an email flow gets rebuilt, a creator partnership starts. Each one changes the paths buyers take, and last quarter's reading was taken on the old paths.
3. Tags and consent settings break without anyone noticing. A theme update drops the purchase event. A consent banner update blocks the GA4 tag even after visitors accept. A landing page ships without UTM tags. None of these throws an error: the orders keep arriving in your store, and GA4 stops seeing some of them, or stops seeing where they came from.
4. A check after the damage is expensive. A tag that broke early in a quarter has put its error into every report and every budget call made since. The checkup costs the same whichever week you run it. The repair does not.

Check again, out of turn, when:

1. Tracking or the site changes. A new theme, checkout, consent banner, tag manager container or domain. Run steps 1 and 2 below within the week.
2. You add or cut a channel. Adding one changes the paths buyers take. Cutting one tells you something only in total orders, because the channels that remain can absorb its credit in their own reports.
3. Peak season is coming. Fixes are cheap in October and expensive in Cyber Week. The Q4 checkup is the version for Black Friday.
4. A platform's ROAS and your revenue disagree. When an ad platform reports a record week and your bank account shows an ordinary one, stop acting on either number and run the checklist.

Ad platforms grade their own homework: each one counts the sales it can connect to its own ads, inside its own window, and none of them is paid to tell you that the total is more than you sold.

The checkup, step by step

Everything here runs on GA4, your store's order report and free tools. Write the answers on one page and keep it. The second checkup is where the first one pays off, because a number that moved is easier to spot than a number that is wrong.

1. Purchases. Put GA4's purchases for last quarter next to the orders your store recorded for the same dates. They will not match exactly, because some visitors decline consent or block scripts, so write the gap down. A gap that grew since the last checkup points to a tag or a consent setting, and it comes first, because every step below reads the same events. Then place a test order and check that the purchase shows in GA4's Realtime report.
2. Sources. In GA4, open Reports, then Acquisition, then Traffic acquisition, and note how much of your sessions and revenue sits in Direct and in Unassigned. The UTM coverage calculator turns those numbers into the share of sessions and revenue that arrived tagged. If Unassigned grew, look first for a link that went out with a source or medium GA4 does not recognise. The UTM builder shows which channel a link will land in before it ships.
3. Claims. Add up the revenue each ad platform reports for the quarter and set it against your store's revenue in the ad platform over-reporting checker. If the claims add up to more than you sold, no single platform report can be read as what that channel caused. The one-hour claim ratio audit runs the same comparison for one peak week.
4. Lag. In GA4, open Advertising, then Attribution paths, pick your purchase key event and read days to key event for paths with two or more channels. That is how long your multi-channel buyers take. Set it next to each ad platform's attribution window: a sale that lands after the window was never that platform's to count, and last-click hands it to whoever touched the buyer last.
5. Targets. Put this quarter's average order value, gross margin, shipping, fees and return rate into the break-even ROAS calculator. Costs and discounts move every quarter, and so does the ROAS a channel has to clear. A target carried over from last year describes last year.
6. Cause. Pick the channel whose claim matters most to next quarter's budget and plan one holdout test: switch it off in a few regions, keep it on everywhere else, and compare total orders by region from your store. The holdout test planner tells you how many days that takes at your order volume. Run it for at least as long as your lag from step 4.
7. Log. The date, the gaps from steps 1 to 3, the lag, the break-even target, and what you fixed. Next quarter, start by reading it.

For a longer list of questions, the free marketing attribution audit template goes wider. This checkup is the part worth repeating.

Where a read fits

Later, if you would rather not work through paths and channels by hand every quarter, a causal attribution read like Causality Engine's is built for that quarterly slot. It takes one GA4 Attribution paths export and shows what each channel caused next to what last-click gave it, with Direct split back to the channels that sent those buyers. Every channel gets a data-health score from 0 to 100 and a next step, and the read shows your paths to purchase, with receipts that check every number against the export. It reads what GA4 recorded, so the store-order comparison in step 1 and the break-even target in step 5 stay on your list. It takes 1 to 2 minutes and costs EUR 99 once per upload, excluding VAT, with a full refund within 30 days, no questions asked. The quarterly attribution checkup sets out how a read fits a quarter. If your budgets move weekly across 8 or more channels, a quarter is too long between visits: Pro, at EUR 299 a month, adds automated GA4 ingestion and continuous attribution. The first finding is free: your browser works out how many days buyers who saw two or more channels take to convert, and the file never leaves your machine.