[abiekatz]

Running an additional product, especially one that takes off requires a lot of resources and attention, is very difficult to manage when your primary focus is on a different business. From Justin.tv and their investor's perspective, they are able to maximize the chance of success of Socialcam while likely maintaining an equity stake. Also, the Justin.tv team can focus all of their energy on growing their primary service rather than managing multiple services.

I like the analogy that having a business with multiple very different businesses is like a multi-front war.