It's obviously not the only thing they look at, but in a situation where, say, two candidates may be very similar, it's something that does. I was wait listed there last year, and when a friend of mine in the program asked a professor why I didn't get in, he essentially said that there were others who had applied previously - sort of an extended wait list type of thing is more what I mean? Like "ah, yes, this person again - I remember this work from last year and am glad to see it again/how it's evolved/etc."