Ad rotation refers to the way your ads are delivered on Google and the Google Network. Your ads will rotate if you have multiple ads within an ad group, since no more than one ad from your account can show at a time.
In the Advanced settings section of your campaign's "Settings" tab, you can specify how you'd like the ads in your ad group to be served. You have two options:
- Optimize (default): Optimized ad serving delivers ads with higher clickthrough rates (CTRs) into the ad auction more often than other ads in the ad group. These higher-quality ads gain more impressions than other ads in the ad group, resulting in higher ad served percentages. By using this ad serving option, your ad group will likely receive more impressions and clicks overall, since higher-quality ads attain better positions and attract more user attention.
- Rotate: Rotated ad serving delivers ads more evenly into the auction, even when one ad has a lower CTR than another. The impression statistics and ad served percentages of the ads in the ad group will be more similar to each other than if you had selected the optimization option. However, these statistics still may differ from each other, since ad position may vary based on Quality Score and CPC.
