Go esports. I've spent $200 on SC2 tournaments this year, far more than I spent on video games.
btw most of that growth is from LoL. SC2 is pretty stagnant although still about 2/3 the size of LoL. Halo 4 barely registered and CoD wasn't even at MLG because Treyarch doesn't care about it.
I don't think the hardcore shooter scene a la CS1.6 really exists any more. Is there any interest among Halo and CoD fans in paying to watch the best in their game?
Of course the premier esports experience as a serious career is South Korean SC:BW (or what's left of it).