I have written about Facebook's AppCenter before and how it represents the focus on mobile and on Facebook's platform... and opens up a monetizable, interaction beyond "Like": "Install". (And by the way: you could easily argue that "install" is a more valuable action thank "like" or "follow"). Here's a screenshot within the mobile web promoting Fab with a sponsored unit that is visual, includes ratings, reveals friends who use the app and, most importantly, a big "install Now" button.
