Most of those value based companies sold to community companies. A community company generally needs to get quite big before they are an acquisition target, but if they do get that far than the customer base makes them worth a lot. I generally think reddit was a bit undervalued - being an internet front page is something they never really exploited.
> Most of those value based companies sold to community companies.
Exactly. Large acquirers typically already have a community, and are looking for additional products and services to offer that community. Meanwhile, community sites are typically more difficult to integrate. Witness Yahoo's struggles with integrating Flickr and del.icio.us.
