The ad group structure in display campaigns is used to segregate and test targeting methods, targeting configurations, ad images, and ad copy. This diagram shows ad group structure in a small display campaign.
Without the structure provided by ad groups, we wouldn’t be able to evaluate the effectiveness of different combinations of targeting and ads.
Some targeting methods require multiple ad groups in order to better control and observe results. For example, when we’re targeting using “custom intent” targeting by URL, we’ll create one ad group per URL targeted. Placement targeting to show ads on specific websites, the same.
By using ad groups liberally in display campaigns we’re able to rapidly evaluate targeting and ad quality.