You can credit the search and price, but for the content and community, the question is why did those come there in the first place? And perhaps search and pric

You can credit the search and price, but for the content and community, the question is why did those come there in the first place? And perhaps search and price are the answer, but perhaps also word of mouth leading a critical mass of users also helped. And then the question is why did word get around in the first place. Marketing? Nice site design? Back to search and price? I can't tell because I started using it after it got big (or at least it feels that way). The upvote system, as always, also contributed a little I'm sure, as an encouragement to produce quality content. That kind of system seems a prerquisite at the very least, if not the reason for a site's success.