Many of the ads that you see on Facebook are shown with you in mind - that is, they're targeted. Whenever you "like" a particular page, you give away a lot of information, tips that turn out to be hints for advertisers. Of course, some people loathe the idea of targeted advertising - but if they're going to use Facebook, that's one battle they're going to have to give up.
And if you're going to see targeted ads, you may as well see the most relevant ads out there. With that in mind, Facebook has begun to ask users to "tell us what you like," in order to help them show more relevant ads.
The new prompt appears when a user chooses to hide an ad by clicking the "x" at the top right corner. After clicking "hide this ad," users are asked why they chose to do so. Users can tag ads offensive, pornographic, and even write-in their own complaints. After this, users are now seeing this new "tell us what you like" box.
Clicking on the link (seen above) takes users to the "Discover Facebook Pages" page. Here, users see a bunch of recommended pages to like, based on their own activity and the activity of friends. Users can also sort these recommended pages by category.
The thought here is to get users to "like" more pages, which in turn will help advertisers better target them. Because if there is anything worse than an ad, it's a completely irrelevant ad.