As with everything else in business, it is partly a unique vision based on what the market seems to be looking for as opposed to what is currently available. The other part is bringing the vision to fruition in a way that caters to the target market in the best possible way.

MySpace was the first, Facebook seems to have perfected it and most that follow are nothing more than imitators and pretenders to the throne. With a few exceptions, that is the basic model that seems to fit almost every success story.