I don't know what Reddit sold for, but while Loopt's $40M was far down from its earlier $500M, it's still a hell of a lot more than the ~$300k valuation it would have had when YC invested in it.
I think he's not just talking about the dollar value of exits, but the value of the founders.
The founders of Loopt, the Reddits, and Justin.tv have done a lot for the YC program (and for startups in general) going forward; arguably these 3 moderate successes financially for YC but having very involved alumni might be worth more than a huge financial success which didn't stay involved with YC.
The comment that I was specifically replying to was this:
"Wow, that's phenomenal. In 7 years, out of 8 companies there were 5 acquisitions (and a couple mergers). I'm sure any VC would be ecstatic to have that kind of success rate."
I don't see how that statement has anything to do with the value of the founders.
He said "5 acquisitions" not "2 (or 3) acquisitions and additionally they have very involved alumni.
That's quite a halo effect that has prevented you from seeing the true "success rate".
Where are you getting 5 acquisitions from?
Reddit, Loopt basically made out.
Infogami merged with Reddit. That's essentially a save face maneuver and doesn't exactly signal success.
Clickfacts - "YC stake acquired by private investors" doesn't sound like that would be a win but a break even. More like "take it off our hands".
Kiko - Sold in an ebay auction for 258,000.
http://gigaom.com/2006/09/05/tucows-bought-kiko/
http://tucowsinc.com/news/2006/09/why-we-bought-kikocom/
I'd give it 2.1 out of 8.