I think club carlson offers a fairly good and underrated program especially for hotels in Europe. See my post on the club carlson credit card for more information on how to get the most out of this program.
With this current promotion you get 10,000 bonus points with a 2 night stay at any club carlson hotel. While this offer isn't the greatest in the world there are several low cost hotels from which to stay for the 2 nights, and 10k points is enough for 2 free nights at a category 1 hotel (with the last night free bonus with the club carlson credit card).
Bottom line: don't book a random stay just for the sake of this offer, but if you have a planned stay coming up, consider looking at club carlson.