When extensions show, an ad is more prominent and, typically, performs better – more people click on it. This article explains how extensions might impact your actual cost-per-click (CPC). For a general introduction to extensions, start with About extensions. See extension performance for more on reporting data.
There's no cost to add extensions to your campaign, but you're charged as usual for clicks on your ad, as well as for certain interactions that extensions provide. For example, when a person clicks on a download button (app extensions), on a call button (call extensions), on a directions icon (location extensions), and so on. Clicks on review extensions and seller ratings are an exception; we don’t charge you for these. Google Ads charges no more than two clicks (per impression) on each ad and its extensions.
The cost of clicks on extensions is set in the same way as headline clicks: the most that you'll pay is what's minimally required to clear the Ad Rank thresholds and beat the Ad Rank of the competitor immediately below you (if any). Learn more about actual cost-per-click
Just as ads in higher positions usually have a higher actual CPC (due to competition and, in part, to higher Ad Rank thresholds), ads with extensions also often have a higher actual CPC due to increased prominence. However, note that the incremental cost of adding more extensions to your ads is often lower than the incremental cost of moving up a position on the search results page. This means that you can often get more clicks for less money by using ad extensions than by increasing your position.
Your actual CPC for ads with extensions is calculated the same way as for ads without extensions – you pay the minimum amount necessary to clear the Ad Rank thresholds and beat the Ad Rank of the competitor immediately below you (if any). For example, if your Ad Rank places you immediately above search results (e.g. in the fourth position) with location extensions and sitelinks, you’ll pay the minimum amount necessary to meet the relevant thresholds with those extensions. Learn more about actual cost-per-click