To who? How do you package that up and sell it to someone?
I've had a service like this in mind for a while and haven't pulled the trigger because I'm a chronic procrastinator.
I guess what I'm getting at is... some data is valuable, but doesn't, at least to ignorant me, seem to have a market for it.
(Edit: BTW, I'd be happy to be proven wrong... for instance, I have this site where the data might be worth something, and the ads aren't worth much: