It's one of the most validating things you can do for a product is go out there and get them to commit to pay you up front.

Twitch launched in June of 2011, and our growth ever since has exceeded even my expectations, which were not small. A year and a half later, the community of broadcasters and viewers has multiplied hundreds of percent.

You want to learn about what's already in their heads. You want to avoid putting things there.

Who you talk to is just as important as what questions you ask and what you pull away from it.

I wish I could tell you the recipe for figuring out who the target user is for your product and who your users should be, but... there isn't a recipe. It comes down to think really hard and use your judgement to figure out who you're really building this for.

The other mistake I think people make is talking to who's available rather than talking to who they need to talk to.

This is true for most new products. The majority of people you're competing with are non-users. They are people who have never used your service before. And what they say is actually the most important. What they say is the thing that blocks you from expanding the size of your market with your features.