Pinterest: A social bookmarking service that lets you share interesting pages you find on the Web on via your mobile device to the rest of the Pinterest community. ….zzz….huh wait, is that a from pitch back in 2006?

While the core concept behind Pinterest is well-worn and has been tried many times by many startups, for some reason this time it seems to be working. Well, taking the world by storm might be more like it. You don’t often see traffic rank charts like this:

Pinterest’s success points to a couple things. First, that social discovery is still a hugely underserved need, and second, that execution can make all the difference between a failed web community and a successful one.

First of all, what the heck is Pinterest? TIME magazine named Pinterest one of the top websites of 2011, here’s how they described it:

Pinterest makes the process painless by offering a Pin It button that lets you grab pictures of your favorite things as you browse the Web. The site then collects the images on “boards” that other users can follow and comment on. Perusing other folks’ boards, featuring everything from picturesque travel scenes to oddly beautiful bacteria, is as enjoyable as building your own.

The concept is similar to sites like Delicious, you get a bookmarklet and you share interesting pages you find on the web – the slant with Pinterest is that mostly focused on images. It’s also mostly women and fashion oriented, but thats not explicit and may change as the site grows.

Why does Pinterest work so well? I think there are a few things the site gets right:

• Make it about the pretty pictures – the aesthetic of the image web has been skyrocketing as digital photography equipment and know-how become ubiquitous. Pinterest provides a highly visual space in which to organize and share beautiful images, and the UI itself creates highly attractive artifacts from these images. Call it aesthetic arbitrage.
• Utilize screen real estate – Pinterest has a great liquid page layout which grows to fit large screens, and shrinks gracefully for smaller screens. The fact that users with 27 inch monitors can stretch and consume copious amounts of content quickly is nicely aligned with the accelerating velocity of content consumption online.
• Physicality of the board metaphor – When you pin something on your board, it sits there like a mini post-it note. As you pin more stuff on, your board starts to “fill up.” You need to be a pretty active user to fill up your board and fill up your “space” on Pinterest. When you pin something up, you probably remember where it is, to go back to it later. Its a highly physical feeling that just seems to makes sense.
• Viral loops galore – Pinterest has all the standard sharing dimensions and tools, they keep it simple and rich with vitality – there are many ways to subscribe, share, and consume and it feels very active.