The application form http://news.ycombinator.com/s2012form http://news.ycombinator.com/s2012form specifically addresses marketplace ideas in this question: How

The application form http://news.ycombinator.com/s2012form http://news.ycombinator.com/s2012form specifically addresses marketplace ideas in this question: How will you get users? If your idea is the type that faces a chicken-and-egg problem in the sense that it won't be attractive to users till it has a lot of users (e.g. a marketplace, a dating site, an ad network), how will you overcome that? From that I suspect the barriers to YC entry with a marketplace startup are somewhat higher.