When GA4 shows you 100 conversions, Meta 80, and Google Ads 60 — 240 in total — but you really only have 100 orders, you've hit over-attribution. Here's why and how DataNostro handles it.
Three attribution models in one conversion
- GA4 (data-driven): distributes credit across all the channels a visitor touched.
- Meta (last-click ad): if the visitor clicked a Meta ad in the last 7 days → 100% credit to Meta.
- Google Ads (last-click ad or data-driven): same for Google.
Each system works in isolation — it doesn't know what the others are sending. That's why the numbers never add up to 100% and every platform claims its own conversion.
What DataNostro does about it
DataNostro can't change how Meta or Google count. But it gives you one source of truth — the tracking log. You see every event with:
- the original
session_idandclient_id - the source UTM parameters + referrer
- a list of the platforms it was forwarded to
- the HTTP status from each platform
When GA4 and Meta show you different numbers, open the DataNostro Activity tab and find the conversion event. You'll see whether it went only to GA4, only to Meta, or to both.
Practical rules
- For budgeting, use GA4 → the "data-driven" model. It's the least biased.
- For campaign optimization, use platform-native numbers (Meta CAPI, Google Ads). The algorithms learn from them.
- For reality, watch the number of orders in your shop (Shopify / Shoptet / your own DB). That's the only unbiased source.
Don't do this
Don't add up the columns "GA4 conversions + Meta conversions + Google Ads conversions" — counted 3×. Marketers who do this believe in a fictional ROAS.