This looks very cool. My company (http://periscope.io) is just now getting to the point of putting documentation online, and -- surprise! -- it's a huge pain and products in this space all seem mediocre.

One deal-breaker for me is that it has to feel like it's on my website. This means templates are not enough: I need full CSS customizability (statuspage.io does a good job with this) or iframe ability. The lack of a great, fully customizable product in this space is why I am currently fucking around with Markdown pages.

It's certainly fair to charge a lot more than you're apparently charging in order to get this customizability -- needing it probably predicts a real business that cares about its brand. (If knol.io becomes a big business I bet you'll end up charging a lot more in general.)

Anyway, awesome job with this! Looks like a great product solving a real problem.