With product extensions you can show users the products from your site that are most relevant to their current query. You're charged the same cost-per-click (CPC) whether a user clicks on your main text ad or any of the offers within the product extensions plusbox; however, you won't be charged if a user simply expands the plusbox without clicking through to your site.
Advertisers using product extensions have found that the additional product information has helped improve the performance of their search campaigns. For example, SonyStyle.com, reported seeing a 9% increase in conversion rates for their ads with product extensions.
It's easy to get started with product extensions. First, log in to Google Merchant Center and add your AdWords customer ID to your account. Then, simply log in in to AdWords, select the campaign and navigate to the Ad Extensions tab. To add product extensions to an existing campaign, click the ‘New Extension’ button. No need to create new campaigns or ad groups, update your keywords or change your ad text.
Product extensions are available to all U.S. advertisers, and now, to all U.K. advertisers, but remain in a limited beta outside of these countries. Over time, we hope to offer product extensions to all advertisers globally.
Posted by Dan Friedman, Inside AdWords crew
