Start-ups to Watch in 2012

3 of 8

Pinterest

Launched in 2010, this invite-only social discovery platform lets users connect through the images, pages, recipes, and whatever else they find on the internet. Think of it as a personal online mood board. Though it has been around for over a year, it quadrupled its number of visitors since August, going from one million to now over four million in just four months. Co-founder Evan Sharp told Mashable: “We didn’t build this company to build a really hot tech start-up…It came out of what we wanted to build—more than the idea to build.”