To increase the popularity in e-sports, you(Valve) should write news about the different tournaments matches as they are being played. This news section should also be the default "front page" in the browser in Dota 2. I know it's not really your job, but if you help to create interesting news or content regarding the e-sport scene, you may increase its popularity by insane amounts.

Write about the casters, interview the players, arrange show matches and have some nice pictures, a little bit of humor and a little bit of "seriousness". I'm sure there's a lot of other stuff you can do to boost the pro scenes popularity. Please try to do what can and more to make this pro scene the biggest it can be.

Also to help the e-sports grow, you should bring back the featured matches.