The current toast of the web is Pinterest, the visual pinboard for collecting and sharing content online. The “pinning” phenomena is spreading from its modest beginnings to appearing in national media outlets. There are over 2.5m monthly active Pinterest users on Facebook. A co-founder of the site has over 500,000 followers on Pinterest. Ron Conway (an investor in the site) remarked that Pinterest’s user growth rate is what Facebook’s was five years ago. Earlier in 2011, it was valued through venture financing at $40m and, most recently, just a few months later, at around $200m.

What is going on here?

Pinterest is growing for a variety of reasons. It enables users to clip things they like. It emphasize pictures over text, which are more visually appealing and easier to digest. Signing up is easy. Pinterest has crafted a fun, whimsical, artistic image. In particular, it has struck a chord with female users, an attractive demographic. Pinterest has added to the lexicon of “like” or “retweeting” or “reblogging” or “upvoting” with the ability to “pin” content and then “repin” it across the site and other networks. A leading expert on marketing to moms, Kat Gordon of Maternal Instinct, remarked that using Pinterest is a “soothing” experience for her.

Despite the hockey-stick growth, doubts exist. Where’s their revenue? It’s likely they won’t make this a focus until the product and backend systems are complete, but note that they already route affiliate links to online shops and are believed to drive incredible traffic to Etsy. Why did Pinterest raise so much money? It was a very competitive round, and the team needs much more technical talent, and in this environment, they’ll need to be aggressive about finding that talent. And, what exactly is Pinterest? It’s a site about discovery and data. On the front-end, users can discover things that they like and organize things they like. On the back-end, it’s a data company, where the company can capture rich metadata around each image.

I’ve been tracking Pinterest for a while now and, to me, the single most important aspect of the site is that it has deeply tapped into an important shift in consumer and purchasing behavior. As we make a decision to search for or buy something online, we are trained to go to Google (or Amazon), search by keyword, and sort through results to eventually make a transaction. In return for that sorting, Google charges for advertising, but in order for it to work, we users have to signal our intent: “Red Nike running sneakers.” But, how did I decide to want these red running shoes in the first place? While Google makes money at the bottom of this decision funnel, the top of the funnel is where “discovery” happens. It’s much wider at the top of the funnel, and harder to pin down where the thoughts originate (pun intended).

A site like Pinterest could help bring some of that discovery online. For the red running sneakers, instead of researching them myself, I may instead elect to browse the pinboards of Pinterest users who are dedicated runners. I could find sneakers on a friend’s board and may have reasonable confidence that this pair could suit me, too. In this manner, I may elect to buy the shoes right after seeing my friend’s board on Pinterest and get to a transaction faster.

If Pinterest can (1) get its users to take pictures of things in the real world with its mobile app and post them online with data and (2) leverage image-tagging tools such as Stipple and help bypass intent-based search on just a small fraction of online transactions, it could be a huge cultural and financial success. This is the promise of Pinterest. Of course, there’s a long way to go and there will be other opportunities to create discovery engines for different types of users, whether broad or niche.

There is too much information online, too many pages filled with stock images and no context. Search engines provide significant utility, but we still have to exert energy to find what we need after results are algorithmically surfaced. The new crop of social media companies help discovery come online and threaten traditional search. With these new tools, users are able to clip and collect the bits of the web that they are most interested in and, in the process, disregard the rest as noise.

Sites like Pinterest, Twitter, Tumblr, Instapaper, Snip.it, Clipboard, and Curisma, among others, all allow their users to decide what aspects of the web (text, media, etc.) are worth saving and sharing, instead of browsing the web from Google, or even Facebook for that matter. Because many of these networks have asymmetric follow/follower models, and because users can “tune” whom they are following, users’ feeds could increase in relevance as items are retweeted or repinned. These networks allow for self-expression, and in doing so, re-sort and re-shape the web we see, and that is a very big shift away from traditional search toward social discovery.