I'm sure it does, but if I'm working on a new developer product how do I make the case that it's the next YUI? I think these sort of line-in-the-sand rules lead to people erring on the side of not doing anything.
Those sorts of estimates are easy. You just go "total market size" * "my potential penetration as a percent". Yahoo would have the numbers available for the former, and you guess the latter.
