I have been playing with a new overture account trying to compare the results to Adwords. I noticed just today what appears to be both Adwords and Overture ads showing on some of my "referrer pages". (Infospace property) In fact I have a page up on my computer now that shows only three ads for a particular keyword- all of them mine. One from Overture and two from Adwords. Obviously there is low competition for that keyword but I don't understand two adwords ads showing for me at the same time.
Looking at Overture and Adwords descriptions it seems that they are both using infospace- are there others that do the same?