Alexis Ohanian in an interview by Christine Lagorio:

We built Reddit in three weeks. It was just Web links and text submitted by users, with Interesting or Uninteresting buttons that you could click on underneath. Simple: That's all it was. After a contentious debate, we added Comments. We knew our business was in our user base, that that was the most important part.

Fascinating how something simply done can have such an impact.