There are two ways the attribution hierarchy is determined in Google Ads:
- If a user is on multiple audience lists in the same ad group:
- The audience with the highest bid adjustment will get impression, click, cost, and conversion attribution.
- This hierarchy pertains to both manual and Smart bidding campaigns (for example, even in cases where the bid adjustment is not directly used in the auction).
- In Smart bidding the highest bid adjustment will apply only to reporting and attribution, and does not impact performance.
- If a user is on multiple lists which are tied for the highest bid adjustment:
- Impression, click, cost, and conversions attribution will be distributed according to a defined hierarchy.
Customer Match is given first priority, with remarketing and similar audiences (including Google Ads and YouTube) receiving the next highest priority. Third priority goes to combined audiences, fourth priority to affinity and in-market audiences. Fifth priority goes to detailed demographics audiences.