“It's a combination of (1) and (3). The basic…”

It's a combination of (1) and (3). The basic plan would be to buy these companies and leave their products running while over time incorporating the social dynamics they've invented into our core products. One thing that may make (1) more reasonable here is that there are network effects around social products and a finite number of different social mechanics to invent. Once someone wins at a specific mechanic, it's difficult for others to supplant them without doing something different. It's possible someone beats Instagram by building something that is better to the point that they get network migration, but this is harder as long as Instagram keeps running as a product. (3) is also a factor but in reality we already know these companies' social dynamics and will integrate them over the next 12-24 months anyway. The integration plan involves building their mechanics into our products rather than directly integrating their products if that makes sense. By a combination of (1) and (3), one way of looking at this is that what we're really buying is time. Even if some new competitors springs up, buying Instagram, Path, Foursquare, etc now will give us a year or more to integrate their dynamics before anyone can get close to their scale again. Within that time, if we incorporate the social mechanics they were using, those new products won't get much traction since we'll already have their mechanics deployed at scale.