My PM perspective on this is that games are dominating the media market primarily because they are a good value proposition in our tightening economy. I think a good thing to shoot for is around 2 hours of game play per dollar spent, e.g. make it so that it's an absolute no-brainer for a customer to buy your game vs going to a movie. Replayability is a major aspect of this, look at how many hours people spent on LBAL and Vampire Survivors despite both having relatively simple mechanics.
