This entire thing was forced in everyone's face until someone out there found it funny. They must had shown the commercial for that movie 100 times a day and they always shown the afro part. It's obviously a clever viral marketing strategy to keep spamming the same thing over and over until someone out there finds it funny. Clearly it worked and now this "afro circuis" thing has been overly hyped as usual.
The same strategy can be found in 4chan known as "forced memes" when the same person keeps posting the same unfunny material everywhere until other people find it funny and post it too.