Mike Elgan

[Commentary] The new model is to harvest social signals from wherever and sell personalized ads wherever. Of course, none of the social networks are going anywhere.

They're still important both to their companies and to their users, and they still play an essential role in user identity and data harvesting and, for Twitter and Facebook at least, as places to display advertising. What's important for these companies from a future-facing business perspective is to have multiple mobile apps that harvest multiple dimensions of personal data that can be applied to highly customized and personalized mobile advertising at multiple locations.

The social networks are falling apart -- they're breaking up into multiple sites and apps that do in a scattered way what used to happen centrally. If you're in the personalized advertising business, why restrict yourself to a single social network? Users don't.