Mark Zuckerberg's profile, located at www.pinterest.com/zuck, isn't very lively. He is following more than 100 other users, but has posted very little content himself. The Pinterest profile is linked to his Facebook profile.
While it's too early to say Pinterest poses a threat to Facebook in any way, the simple content sharing site can easily be called the hottest startup of 2012. The site reached 10 million unique visitors extremely fast; it has more than 2 million members (connected through Facebook), and it's already used by more than 100 brands.
At the very least, Zuckerberg must be curious to see what this little site has been doing to become so successful. Facebook has never been too shy of adopting successful concepts seen on other services; for example, its Subscribe button, launched in September 2011, is an obvious nod to Twitter's Follow.