Why Y Combinator Is The Hottest Startup School In Silicon Valley

It has an acceptance rate similar to that of an Ivy League school, and a track a record for producing billion-dollar-valuation startups, like Dropbox and Airbnb.

Over the weekend, YC founder Paul Graham tweeted that 37 companies out of the program's 511 startups are either worth at least $40 million, or have sold for that amount.

We first saw the news over on TechCrunch.

The most surprising success story for Graham: Rap Genius, the startup that annotates rap lyrics, literature, and poetry.

But what is it actually like once you get accepted into Silicon Valley's most prestigious accelerator?

Last year, we compiled thoughts from several Y Combinator founders about the incubator.