Exits are a stupid test for what they're trying to measure here. By that standard, Airbnb and Dropbox are failures. Exits are a reasonable test for investments made, say, 10 years ago. But none of the incubators are that old yet. So the right way to judge them is by the valuations of the startups they've funded. Unless the venture business as a whole loses money, that will be a lower bound on the eventual exit number…
If the startup is profitable and self sustain itself, does it count as success or failure?
It can mean "ramen profitable" or something slightly better (like it can pay the rent and the founders a small salary)
Either way, not good. You don't need a home run, but you need something that can "fly for itself""
Getting there is tough, most startups are like making a rock fly