When entering the Google Ads bid auction, what factors determine ad serving order?

The ad serving order in the Google Ads bid auction is primarily determined by the combination of a competitor's maximum cost-per-click (CPC) bid and the estimated click-through rate (CTR). Google Ads uses a formula to assess the Ad Rank for each advertisement, which is a crucial component in determining which ads get displayed and in what order.

The maximum CPC bid reflects how much an advertiser is willing to pay for a click on their ad, while the estimated CTR indicates the likelihood that users will click on that ad when it is displayed. By considering both factors, Google can accurately gauge the overall value of an ad and rank it appropriately in the auction.

This approach ensures that not only are high-value ads that bid competitively rewarded, but also that ads that are likely to be clicked on (even if they bid less) can achieve a better position due to their potentially higher relevance to users. This balance aligns with Google's emphasis on providing relevant ads to users while also rewarding advertisers who are willing to invest in their visibility.