Amen to that. Those guys have done an amazing job. What especially impressed me was how involved they are in their own community. I posted a presentation on scribd on APIs and one of the founders (Jared) commented on it personally. A little thing, but very impressive to me.
Any startup that gets huge traffic (except from porn or "illegal" music sharing) will have VCs all over them.
As a first approximation it's as simple as that. If you have a lot of traffic you matter, and if not, you don't.