Google quietly announced on Google+ a new version of sitelinks named account level sitelinks. What this means is that sitelinks can show with any of the ads in your account automatically.

“Campaigns and ad groups that don’t have campaign or ad group-level sitelinks, respectively, will automatically use sitelinks created at the account level,” Google said.

Here is a sample:

AdWords has had dynamic sitelinks and many other flavors of it for some time. This seems to be a way for Google to show sitelinks more often in the AdWords results.

Here is how they work:

More details can be found in this help document.

Forum discussion at Google+.