Honestly, 10 have already exited, and they have at least half a dozen impressive companies in the pipe.
Are these companies AirBnB or Dropbox? Probably not, though Twilio is legit.
looking good so far: Twilio, SendGrid (TechStars), Wildfire (fbFund), MakerBot, TaskRabbit (fbFund), Smule/Khush, Viki, Medialets, Zozi, ElaCarte (YC), 9Gag (500), ReadyForZero (YC), several others @ Series A/B/C doing pretty solid.
smaller but growing well: MindSnacks (DreamIt), 955 Dreams (500), PicCollage (500), Kiwi Crate, Visually (500), AppStack, MyGengo, Erply (SeedCamp), GinzaMetrics (YC), Farmeron (SeedCamp), ZenCoder (YC), Fitocracy (500), StyleSeat.
10+ modest early exits to Google, Twitter, LinkedIn (x3), Amazon, Groupon, Cisco, Facebook, ReturnPath, DemandForce, etc.
(apologies to any juggernauts or others i left out!)
DMC
our 2nd check is a great confirmation of whether we were right or not... happens ~20-30% of time after 1st check.
"500 due diligence = mentor filters + quick 1st check, followed by thoughtful 2nd check based on metrics"
2) 500 is usually a minority investor in following rounds, so decisions still likely made primarily be lead investor
3) if companies and follow-on investors are more worried about our decisions & subjective assessments rather than the company fundamental business metrics, then there is already a problem.
we are in this business to be successful and make money. much as aim to help all of our founders, we sincerely hope they are too.
Basically, you're going to have a run of bad cards (companies) and a run of good ones. But if your decisions are consistent, and adjust to migrate towards successes, you'll end up ahead no matter what... assuming you're moving in that direction.
It's really not spray and pray, just as high stakes poker doesn't really have anything to do with luck.