Spread the word, tell your friends.
Create content and be entertaining.
I know so many people at school and real life that think that TF2 eSports was and is a joke, but after showing them the charity event, as well as streaming what I do, many of them say that it's some of the best fun they've seen watching video games. Basically, just show people that TF2 is awesome, and it will grow.
Because it deserves it.