The majority of the market is the dude-bro that buys CoD and sports titles and is open to big budget cinematic games if theres enough hype behind them.
So, it would be the average as you described.
It's obvious the hardcore is not the majority. If it was, the Vita and Wii U would've been sucesses. Hardcore is about 10m. But they are also the early adopters so they are extremely important at the start of a cycle.
Oh this applies only to Sony and Microsoft.
If its Nintendo we are talking about, they appeal alot to the first segment you described. The casual gamer was it? When they do that them their systems sell alot, but the software not so much because its the average and harcore that buy lots of games. The casuals will only buy the Nintendo mainstream titles. Wich is why 3rd parties usually give up them.
