Why Do Meta and Google Both Claim Credit for the Same Sale?

Open your Meta dashboard, note the conversions. Open your Google dashboard, note the conversions. Add them together and you will often find both platforms have claimed the same sale. Sum the platform reported numbers and you overstate performance, sometimes badly enough to justify spend that is actually losing money.

Why it happens. Each platform reports the conversions it believes it influenced, using its own attribution window and its own view of the customer journey. A customer might see a Meta ad, later search your brand on Google, and buy. Meta counts it because its ad started the journey. Google counts it because its click closed it. Neither is lying by its own logic, but you cannot add their numbers, because they are both counting the same rupee of revenue.

The consequence. A founder summing platform reported ROAS across channels sees a blended number that looks strong, scales spend on the strength of it, and only later notices that actual bank deposits do not match what the dashboards promised. The gap between reported performance and real revenue is the double counting.

The sanity check: Marketing Efficiency Ratio. MER is total revenue divided by total marketing spend across all channels. It cannot be inflated by attribution overlap, because it ignores which platform gets credit and simply asks how much revenue every marketing rupee produced in aggregate. It is blunt, and it does not tell you which channel is working, but it is honest in a way platform reported ROAS is not.

The rule. When your platform reported ROAS looks strong but your Marketing Efficiency Ratio does not, believe the Marketing Efficiency Ratio. Use platform numbers to compare channels against each other and to guide optimisation, but use MER to judge whether your marketing as a whole is actually profitable.

Have you compared your blended platform ROAS against your MER, and how far apart are they?