I am sure most of you have heard by now about the “20% rule” that Facebook recently instituted for advertisers and page administrators. If not, the basic premise of the rule is that any image in a Facebook ad can have no more than 20% text. This goes for traditional ("like") ads and sponsored ads. The rule also applies to page cover images.
Facebook always has their eye on the customer experience, as they should, and this new regulation no doubt addresses an area that they must have seen as exploitable and threatening. Given the growing adoption rate of newsfeed ads, it makes sense that Facebook would be concerned about the content that they are inserting into the news feeds of unsuspecting users.
Generally, Facebook is very lax in enforcing their page guidelines. Just go through your page feed right now and click on a few of the pages. I am sure you will see promotional language in cover images and maybe even a non-app contest: both grounds for a nastygram from Palo Alto, if caught. The problem is that with hundreds of thousands of pages in existence, it is very difficult to police all of them regularly.
Well, Facebook is taking the new 20% rule very seriously. Not only have they been rejecting countless ads that are submitted for approval, but they have been going through advertiser accounts and rejecting paused ads for violating the rule. Fine, right? Facebook has all the right in the word to reject these ads if they violate the rules.