The Difference is Discovery

From SearchEngineLand this post on Beyond Google: Social Media Engines First, Other Search Engines Second points out the essential between social discovery and anti-social search (emphasis mine):

To me, search engines are places where people search, they express an active desire, usually through a keyword search. People don’t go to Digg because they’re looking for something. Instead, they want to discover things, to see what’s new, be entertained. That’s not search.

The unique aspect of OthersOnline as a service is that it truly is discovery, and this discovery happens without having to be on a particular Web site. Through a browser extension and through Web widgets, it is totally user-centric - no matter where you go, there you are.