Pinterest engagement metrics are (at least as of six months or so ago) higher than those of Facebook, Twitter, and Tumblr, and users have much more clearly defined levels of purchase intent.
In a world where Tumblr and Instagram hit star-studded exits, I would be incredibly surprised to see Pinterest fail.
I agree, its actually the only one on that list that doesn't suffer from underwear gnome syndrome in my opinion. (Yes, I know Facebook makes money but I claim that emperor is naked and on the way out)
Its probably not a coincidence that its also the only one that you can derive value from as a user without engaging in "social" mode. I bet Amazon will scoop them up like they did Goodreads - same sort of thing, much bigger niche.
I guess it would be helpful to know the number regardless. Revenue as in gross, or at least the number of paid subscribers. But I think if they were able pull in this new round of funding, they must have some good number of sells lately.
There are a lot of websites with a lot of users but they die quickly too.
In a world where Tumblr and Instagram hit star-studded exits, I would be incredibly surprised to see Pinterest fail.