Glossary
What is cross-campaign conversion attribution (performance max)?
Melvin Salas1 min read
Short answer
A Performance Max campaign's reported conversion count is not guaranteed to reflect conversions that campaign alone drove. Google's automated bidding and attribution systems use signals and assist paths that can span multiple campaigns you're running at once, and standard per-campaign reporting doesn't fully separate out that overlap. This means two campaigns can each report conversions that were partly influenced by the other, so comparing their standalone numbers, or cutting one because its number looks weak, can be comparing figures that were never fully independent.
Every conversion tracked by Google Ads goes through an attribution model that decides which touchpoint(s) get credit. With Performance Max, that model operates across a campaign that itself spans multiple channels (Search, Display, YouTube, Discover, Gmail, Maps) and is optimised by an automated bidding system that shares signals across your account, not just within one campaign's boundary. Google has been explicit that Performance Max is designed to find incremental conversions across its channels using account-wide signals, which is a different reporting unit than the clean, walled-off campaign totals you get from older, single-channel campaign types.
The practical effect shows up when you try to rank campaigns by efficiency. If a Performance Max campaign and a standard Search campaign are both live for the same account, a user's path to conversion can touch both, and the conversion gets attributed according to the platform's model rather than split cleanly by which campaign 'deserves' it. A campaign's standalone reported conversions are a reporting construct, not a certified measure of that campaign's isolated contribution, so a founder deciding which of two campaigns to pause based on a side-by-side conversions column is making that call on numbers that may already overlap.
We run Meta and Google as one system
Riibon runs Meta Ads and Google Ads together, so one platform does not quietly claim the demand the other one built, and ties both back to outcomes measured outside the platforms.
Ask the Riibon app how your Meta and Google campaigns compare on the same terms. Access starts with a short call: we look at your ads together, then run them for you or set the app up with you.