In fairness, they all founded Justin.TV. It's significantly easier to get a third startup if your second startup was a success, and I think the OP was talking about having two failures in a row.

I have nothing but respect for the justin.tv people and product, but may I ask what criteria you're using here to define it as a success? I would have called it a pivot, albeit a great one.

Success = has traction in a market large enough to be of interest to a VC. Usually that's the hard part of entrepreneurship; if you can demonstrate you've attained that once, getting funding for subsequent endeavors is a lot easier.

Would you say Digg was a success?

From the perspective of "Is Kevin Rose likely to get funded again?", absolutely.

From a user perspective or the perspective of one of the founders, it's less clear. I remember ojbyrne being less than happy about how it turned out.

The fact that they even had users is more than 90% of startups, manage, though.