Pinterest is the greatest cash cow in the making that nobody's talking about. (I mean, they're talking about it. But nobody's talking about it the way they're talking about Snapchat, which is kind of nuts. Pinterest is the perfect ad platform, outside of Google, for a demographic almost every major consumer brand cares deeply about.)
This is a great point, and for advertisers it seems absolutely correct. In part because the purpose of the use and her mindset and the advertisers are in synch. Perhaps somewhat similar is linkedin (now worth ~$20B). FB, Instagram, Snapchat, and Twitter have emerged to be far more disruptive socially as communications platforms. This puts advertsing and the user experience at something of a conflict in terms of functionality (& ignoring here the privacy/data collection debate, which is a different issue). So the reason snapchat is 'hot' right now to FB and VCs is this disruptive potential to entities with deep pockets.
What is interesting, IMHO, is to see if the network effect is really critical, or if the service can be repicated by a thrid party. What I think we will see soon is that people will maintain a network on one site and not necessarily use it; they will turn to other platforms to communicate on an ad-hoc basis. The ad-hoc platforms will have significant value, but wheras instagram and twitter were additional platforms for audience aggregation, the next wave will be service layers where you communicate to your network by "porting over" your contact base, as needed. The only reason I'm bothering to ramble on is that I'm not sure FB wins the game buy buying out SnapChat. That worked for instagram, which had a sticky network and people didn't leave it. For SnapChat, the whole premise is LNT...so why feel stuck to it? Once FB owns it they will track the hell out of everyone using it, so the LNT value prop dies. But the demand will surely remain if the service can be cloned.
I think all they want to say to advertisers is "we have the most active social platform". They can figure out, given enough time and assuming they have patience, how to effectively monetize the snapchat users.
I think differentiating Pinterest ads from content will be tough. The company had previously been rewriting pinned product URLs to include Pinterest's own referrer code. (Users didn't like that.)