Pinterest may be the hot new social network on the web, but the idea behind the site isn't exactly new — in fact, it dates back to at least 2006. Writing for GigaOM, Yelp co-founder David Galbraith has briefly detailed the history of Wists, a site he launched six years ago that is functionally quite similar to Pinterest. "I get too much credit for RSS and for Yelp," Galbraith says, "but the one thing that I can unashamedly claim to have invented is visual bookmarking." Wists let users add images to the site using a bookmarklet, and just like with Pinterest, much of the community took to using it as a sort of virtual shopping list — the site even adopted the tagline "social shopping."

So where did Wists go wrong? Galbraith provides a few potential reasons. For one, he never acquired the resources necessary to turn the site from a "quick and dirty prototype" to something slick and polished like Pinterest. He also feels that the site launched too early, as networks that could help drive growth like Facebook weren't near as big as they are today. "The lesson to be learned here is that first to market is not as important as sometimes claimed," he explains. "Most successful internet platforms are second or third generation versions of an earlier idea." Wists is actually still live, so you can check it out to see what Pinterest might have looked like had it launched a few years ago.