Overall industry is reported at about $9 billion.

The question is, ¿How do I make Lucrative games?. The fact that you''ve developed any Video-Game doesn''t guarantee that you can made much money.
Video- game industry is the most competitive sector in the software development. There are so many game-developers waiting for take an oportunity that allows them to gain a good place in the market.
Today, a game that is offered like books or Music CDs tend to be piraced. If you plain to make a single player game such Doom3 or Tomb Raider, you are outdated.
Many people think that buy a $30 game is a foolishness, while they can get the same piraced cd at $2. These games can be instaled many times; and once you finish it, it becomes boring. That is the reason by the Game bussiness is not profitable these days.

But there no reason for leave your projects. Try to make online games that permits massive interaction. You must provide a server application that manage internet sessions of your game. you will receive money by the connection service, not for the game. Take a look of Underlight bussiness style.
At last, I suggest to you make a trade study about your projects.
Try new things, make non convensional games. It''s up to you.
I wish you glory in which you undertake.
Bye.

Game programer. FreeLance