What you are describing is known as the "chicken-and-egg problem", and if you search HN on that phrase, you'll find a lot of previous discussions and advice. T

What you are describing is known as the "chicken-and-egg problem", and if you search HN on that phrase, you'll find a lot of previous discussions and advice. The short version is that you will probably have to resort to non-scalable means of priming the pump-- basically, identifying a subset of users you can persuade (financially, if necessary) to produce enough seed content to get the ball rolling.