The vast majority of Pinterest users are over 35 and the average age is 40. Roughly 80% of the users are also female. Given that, I would be surprised if the early adopter of Pinterest was your stereotypical 25 year old male developer that these companies look for.

...and the purpose of that young guy's site has turned into showing pictures of grandchildren to grandparents.

I thought the hivemind determined pint' was one of those middle age middle america housewife demos?

Those two statements might be completely valid but don't necessarily disprove my point. :-)

I am sure there are old people who suck at this stuff, as are there young people who are great at this. The point here is that you can't sweep people with a broad brush using one parameter. You get to know the people and figure out whether they would be the right people to build your team without going by silly filters like age or sex or whatever.