Decrease CTR rates as users are sent to specific pages of your site
Show your business address, phone number, and a map marker with your ad text
Allow targeted remarketing list users to land directly on specific pages of your site
Allow advertisers to give users the option to land directly on specific pages of your site
Sitelinks can take people to specific pages on your site—your store hours, a specific product, or more. When someone clicks or taps on your links, they skip right to what they want to know or buy.
Read more here: https://support.google.com/adwords/answer/2375416?hl=en
An ad extension is a type of ad format that shows extra information about your business “extending” from the text. Some extensions can be added manually and others are automated.
See how a business like Main Street Flowers uses sitelinks, call, and location extensions to enhance its ads. By adding extra pieces of information about the business to their ads, they’re giving customers more reasons to click.
The most common types of mobile extensions are call, location, sitelink, and app.