The way I see it is that Cena is boring as fuck, thus he can't draw ratings. I think all his supposed sales are fake, as well as crowd chants, fans, etc. You can't be liked if you are boring as fuck. Turning him heel doesn't automatically make him entertaining. Just make him entertaining. He can be face, heel, whatever.
Oh by the way, I want to commend you guys over here, for the past few days or week you have actually be discussing wrestling. Before that, for the past year, it was dead in here, because of whoever's idea it was to not create topics in the wrestling forum. Great idea to get new fans in here!