Annualized AAA games.
I mean, the financial aspect of it makes sense. I know why Activision, Ubisoft, & others do it.
But I am a bit perplexed that people haven't burned out faster on the model. After a couple years of it, my interest level in keeping up with a series drops so much. I need to take a few years off before I can build up any excitement for another one.
Not many franchises can afford annual releases, but these franchises are so popular that a core fanbase buys the new game every year, and there's a ton more people that buys a game every two or three years, so they don't get burned. And then there's people that buy an AC or a CoD game, play it for a couple of months and then don't play anything else until next year because they don't care that much about gaming and they have other hobbies. Also, non hardcore gamers are way less obsessed with 100% completion and achievements so they don't get burned on grinding XP or finding collectables.
Besides, the fact that a game follows a well known, familiar formula with a few new twists is actually a positive for a lot of people. You know what you're buying.
There's a lot of good reasons as to why the model works. It doesn't always work, though. People got burned on Guitar Hero because too many games came out (much more than one per year!) and there weren't enough variations on the formula. For all the shit CoD and AC get, they offer a new story and new maps/world every year. Guitar Hero just offered new songs.