Sitelinks are an important part of successful ads. They show value to potential customers before a click occurs, while also being (along with other extensions) a factor of ad rank. User interaction with sitelinks is so strong that you should consider them a basic part of your ad text - title, description, display URL and sitelinks. Optimize the messaging in this space routinely, just as you do with ad text.
Many advertisers aren’t taking advantage of this excellent feature just yet, so before we start optimizing you may need to implement them. Adding sitelinks boosts the average CTR on an ad by 10-20% (+20-50% when the search is one of your branded terms), so that implementation should be time well spent.
Make sure to have at least six active sitelinks for desktop and four active sitelinks for mobile, but remember that you can go all the way up to twenty total per ad group or campaign. Sitelinks allow 25 characters for the link itself, and that space allows for testing. We’ve found that somewhat shorter sitelinks are the most effective, though, so try to keep them closer to 18-20 characters for desktop and 12-15 characters for mobile. Thank for your visiting.............
Sources: Google Adwords..
Read more about this Visit Google Adwords official Blog
Keep Reading and Keep sharing!!!!!!!!!!!!!!!!1111111