Meta and Google both claim the same conversion

When Meta and Google both claim the same conversion, it means each platform has recorded one sale or lead as its own result, so the platform totals add up to more than the business actually won.

Why it happens

Each platform attributes conversions on its own terms. Meta can count a conversion after someone saw an ad and later converted, even without clicking. Google can count the same conversion after a click on a search ad. Each uses its own attribution window and its own definition of a touchpoint, and neither knows what the other saw. So one person who saw a Meta ad, then clicked a Google ad, then filled in a form is reported as a conversion twice.

A simple illustration

Imagine one lead comes in. Meta reports 1 conversion. Google reports 1 conversion. Your CRM holds 1 record. Add the two platforms and you have 2 conversions for 1 lead. Run that across a month of campaigns and the platforms can claim far more than the CRM ever received. The numbers in this example are illustrative, not client data.

Why it affects your budget

Budget tends to follow whichever platform reports the best result. The platform with the more generous attribution window looks the strongest and attracts more spend, whether or not it contributed more to the sale.

How to find out how big the overlap is

Add up the conversions every platform reports for a period, then compare that total with the unique leads in your CRM for the same period. The difference is your overlap. The attribution gap calculator does this sum for you. Then check the attribution window each platform is using, since a wide window inflates its count. Finally, rank your channels by closed revenue in the CRM, not by reported conversions, and see whether the order changes.

What to do about it

Pick one reference point for outcomes, and use the CRM, which records what actually closed. Credit each lead or sale once, under a single model agreed in advance, instead of letting each platform credit itself. The full mechanics are in why your ad platforms don't agree with your CRM, and the quickest way to size your own overlap is a free marketing data audit.