Dynamic callouts are generated based on the information on your website, helping reduce the amount of time you spend managing individual callouts. However, it’s important to continue adding and optimizing callouts because dynamic callouts may not show for all advertisers. You can add your own callouts at the account, campaign, or ad group level [https://goo.gl/LlX636]. We’ll always prioritize showing the callouts you provide over dynamic callouts.
Here is an example: In this example the advertiser’s landing page mentions potentially useful information like “25 years of experience,” “Book online,” and “Certified technicians.” With dynamic callouts, this callout text will dynamically appear beneath your ad text, at the top and bottom of Google search results.