In the middle of February [2/14/12] Google posted another update to improve your ad’s quality and relevance to the searcher. The benefit of the update is the ability to more clearly display deeper “site links” links back to your site.
“We’ve talked before about how useful ad sitelinks can be. They give users more options, and deliver advertisers more clicks. On average, the clickthrough rate is 30% higher for ads with sitelinks than those without.”
“We’ve continued experimenting with new ways to make sitelinks even better. Today, we’re taking the covers off one of our strongest performing experiments. It works by incorporating text from ads in your account that are related to your sitelinks. The easiest way to understand things is with an example:
Say you’ve created sitelinks for your pizza restaurant campaign, and your ad displays sitelinks as shown here:
Now, let’s say your account also includes the following text ads:
With this enhancement, your ad could now look like this:
To be eligible, your ad with sitelinks must show above Google search results and your account must contain active ads closely related to the sitelinks in your campaign.
In testing, people reported that ads with enhanced sitelinks were more useful and relevant. And clickthrough rates were significantly higher than the same ad with traditional 2- and 3-line sitelinks.”