charizardpal, I might be wrong, but I think ありがとう is used after a favor is done and not before. I don't think ありがとう and お願いします can be freely switched around.
Kyle, watch out with that Google statistics. When first I came here to Japan forum I had a piece of Japanese grammar that I didn't know if it was right. A japanese had told me it was correct, another native speaker had told me not and google returned thousands found matches. Then here MMM and Nagoyankee confirmed it was an error (not saying anything for this OP case coz the number returned from your search is pretty conclusive
).