I thought for sure this topic would have been exhaustively covered in this forum but a "quick search" attempt yielded nothing on topic.
My first inclination would have been to think that Google and others would treat these social linkages as very weak IBL's, and almost completely discount any linkages made from them.
Then I performed a few keyword searches on del.icio.us new search engine http://del.icio.us/search/?all=hotels and was pleasantly surprised at the quality of the results. So I'm almost completely reconsidering the proposition.
Has anybody had any experience with this?