I think this will only be abused by a small set of people. Likely those that would abuse any type of policy. Personally, I've returned plenty of things, but only due to problems with them, not because I disliked them. I'd have to _really_ dislike a book or feel like I was misled by the blurbs to return a book.
I think that you'd likely see more people trying books by new authors or ones they usually wouldn't because of the return policy.
I also do agree that *absolutely love* is a wee bit strong
It's also easy enough to discontinue of it doesn't work.
My $0.02.