Funnily enough, ratings went up when Edge won the belt the first time. Only for him to lose it in 3 weeks...
But when you think about it, most of Edge's reigns have been transitional, or simply being in the right place at the right time.
They had to take the belt off Rob Van Dam, gave it to Edge for a month or so. Undertaker is injured, so is Kennedy, Edge to the rescue. WWE needed a swerve at ONS, give the belt to Edge so he can hold it for Punk. Once again WWE desired a swerve (or they just didn't want Triple H to be pinned by Jeff, you decided) so Edge gets the belt for a month.