Good point. Another interesting datapoint would be (and this is something that only PG or other YC founders can answer) to see what is the scope of the original vision (eg - change/revolutionarize industry XYZ) of the founders and where they end up (provided they stay in the same space). The original vision is of course going to change, but if a large number of founders are scaling down their original idea, that is an interesting data point. It may be possible that 3 months of iteration may not be sufficient time for certain types of startups. (Again, without any actual YC experience, I am simply speculating).