In the last Dota II tournament 5 guys won $6,634,661 between them. One of them was 16 years old and had just moved from Pakistan to the US. The rest were early 20's. It's a huge thing. Sponsorships, software and hardware companies jumping all over it, Monster are in on it etc. The tournaments are held in stadiums that are sold out and watched by literally millions online which has the PC hardware companies and Monster etc all over it knowing their sales will skyrocket. It's always been the cool thing to do to pass off 'nerdy' things as just that but being among the best in the world in video games and playing on a team with similar players, on a team that's sponsored by a load of other companies can earn you millions of dollars per year.