What it's like to work at Twitch, the $970 million company that's turned gaming into a full-time job

Twitch is a site where viewers go to watch people play video games. It seems like a niche market. It's not.

Each month, more than 100 million viewers visit Twitch.tv to watch the best gamers in the world play their favorite franchises, from League of Legends and Dota 2 to Minecraft and HearthStone.

The live-streaming platform grew from humble beginnings. Video broadcasting site Justin.tv spun off its gaming content to a new site, Twitch, in 2011. Acquired by Amazon for $970 million last August, Twitch is now the fourth-largest site in the US in peak traffic.

I recently visited Twitch's headquarters in San Francisco's Financial District, and discovered those gamers turned tech moguls are really living the life.