One big difference with the sports genre however, is that you have the year stamped right on the label. Unlike other genres that can seem pretty new for a couple years, NBA 2K8 looks a bit old on a shelf next to NBA Live 09.
The thing that makes this question tough, is that I don't know how educated the majority of the sports video games public is? I know that most people on OS are very educated. We understand the games, their competition and debate every nook and cranny between them. We understand that a 1 year old game with good downloadable content can be just as good as a new game.....But what percentage of the market does know that? What percentage of the market sees 2 games on a shelf and simply assumes the one with the later year on the label is the better game?