When I moved my books to Apple’s iBooks platform, I was sort of surprised that “Thief’s Odyssey” took off so well, and that “Kick” — my leading book on Amazon — did not. Today’s sudden appearance in the “Top Sci-fi & Fantasy” category on iBooks warms my cold, shriveled, heart. Now that sales are picking up, all I need to do is figure out which color Lamborghini best fits my rakish personality.