Sigh.
YC has a lot of cachet and no doubt opens certain doors, but founders should never drink too much Kool-Aid. For all of the wonderful things YC provides, the success of YC startups basically follows the same power law distribution you see across the Valley and no founder should delude himself or herself that being part of a "club" guarantees success in today's market.
Just look at the experience of the founder of Dating Ring (YC Winter 2014)[1]:
And so we focused on growth. For a year, my cofounders and I worked 100-hour weeks, all major holidays and weekends. We gave up social lives and had one of the most impressive graphs at the crazy 78-company Demo Day YC hosted – 60% MoM revenue growth, with 25k in revenue for March.
We had more press and name recognition than any other company there, and my pitch was named as one of the top 8 by TechCrunch.
Out of the 500 investors there, only one invested.