There are games that sell systems. The important thing for any system is to have a wide variety of system sellers in different genres. For instance a great platformer will sell a bunch of systems to one group, then a great golf game will sell to another group, a great party game will sell to another, a great football game to another and a super FPS to another group.
To go further, lets say a system has a great FPS game come out and then another great FPS and then another great FPS. All three of the games will probably sell well but after the first game very few additional systems will be sold. The group that buys systems to play FPS games will mostly have already bought the system after the first game and the probability increases after the second. So the second and third FPS games won't be system sellers although they would have been if they had been released first.
Great games that are the first released in their genre have a good chance to sell systems. Great games released in already represented genre's and by extension great sequels on the same platform sell games but sell fewer systems than the first release.








