Back in March, I got fed-up with my desktop book-tracking software (Delicious Library) after an update trashed my custom fields and covers. And it did a lousy job with e-Books vs p- Books anyway.
So I tested Goodreads, LibraryThing, and Internet Book Database and settled on Goodreads. I was not aware of Shelfari. And I'm too lazy to move 400+ books now.