Stewart Butterfield & Caterina Fake
For onetime online-game designers Stewart Butterfield and Caterina Fake, Flickr initially was a lark—a way to let people share photos as they text-messaged. But their sideline took off when they added a breakthrough more social than technical: People could tag their photos and others’ with labels, so they could be found and grouped more easily. Communities formed around groupings, helping attract 1.5 million users, 60 million photos—and, last March, Yahoo!, which bought Flickr for an undisclosed sum.
Turns out Yahoo wasn’t interested just in photos. “Caterina and Stewart are very good at figuring out how to create communities,” says Yahoo co-founder Jerry Yang. One contribution they’ve already made is helping spawn Yahoo’s My Web 2.0, a “social search” site where people can share online searches with others.