For me, the longlist and the shortlist of various book awards means a lot. Someone else has gone to the trouble of pre-reading a book for me, and making a judgement call. It saves me the time of reading *everything* published in a given year, or genre, and let's me start with some of the best books.
So, a shortlist for an award either gives me a ready-made list of titles, authors and/or illustrators that I might be interested in (if I have enjoyed books that have won the award previously), or it gives me a list of books to avoid (if I haven't enjoyed previous award winning titles).
I've learnt that I generally don't enjoy books that have won the Man Booker Prize for Fiction, but I often enjoy books that have won the Commonwealth Book Prize. I have a friend who is the complete opposite to me - she actively seeks out anything on the Man Booker Prize shortlist.
Some 2011 book award winners include
So, does it make a difference for you when you see "award winner" on the front of a book cover?