We can tell which founders went to the same school. We can ask people who teach at or went to school x about applicants from there. If they went to a school we know about first hand, we can ask more specific questions about what they did in college. If they went to a big hacker school like MIT, we can suggest that they recruit friends and/or launch their beta there.

It also gives you the data you need to continue testing this theory.

He could always ask them after accepting (or even rejecting).

makes sense. thanks.