There are three extensions every marketer should be using to enhance their text ad: 1) Sitelinks 2)Callout extensions and 3) Structured snippets.
1) Sitelinks: It directs to specific sections of the website. Sitelinks are additional links that appear just under the text of your search ads, directing users to specific pages of your website.
Sitelinks are easy to manage as system automatically displays the best performing or most relevant sitelinks for each query. It helps to increase CTR and eventually the conversions.
It is recommended to implement 8-10 active sitelinks/ campaign. It should be clearly mentioned on sitelink title what users will find on the landing page.
2) Callout extensions: Callout extensions are short, specific (25-character) snippets of text. They can be used to highlight information about value-adding attributes of the business, products, or services.
Keep your callouts as short and specific as possible, and include at least six of them in your campaigns.Consider callouts that are unique offerings.
3) Structured Snippets: Structured snippets allow you to describe features of a specific product or range of products or services offered by the business before users click on the ad.
When you give users specific information about what you're offering before they visit your website, they'll be more likely to convert after clicking.