[loumf]

A lot of people call this a chicken-egg problem. For some reason, that's supposed to make it seem hard to solve, when in real life, anybody could start a chicken farm very easily.

You simply buy chickens.

If your question is how do I start a chicken farm without buying chickens, then you have made the problem unnecessarily complex.

The thing is, though, when you buy a chicken, you can be relatively sure that you will get eggs. And you can be sure that if you have eggs, it's not too hard to get chicks.

Your real problem isn't how to get content (that's simple, you buy it), but how to then get users that want that content. And then, how to get some of those users to make content.

(to answer your direct question: StackExchange was seeded by JoelOnSoftware and CodingHorror readers -- it was a closed beta until they got enough content. In other words, Joel and Jeff already had chicken farms, and they donated a bunch of them to StackExchange)