The original investor was Peter Thiel (who is the Godfather of the PayPalMafia) and Sean Parker joined the board (he was the guy who introduced Peter to Facebook).
Hartz has seen how the PayPalmafia, by investing in a recent generation of start-ups, has upgraded the quality of start-up know-how in a way that is similar to Y Combinator.
Even as New York entrepreneurs can rub elbows with the founders of Foursquare at tech events, the overall scene still lacks the critical mass of entrepreneurs who have successfully exited billion-dollar companies, are starting again and ready to help local entrepreneurs or its own PayPalMafia.