Web 2.0 moves us closer to frictionless (free, instantaneous) communication, but we were already pretty close.
We have a productivity paradox. Web 2.0 (including social media) is radically transforming society and entire industries -- Facebook has about 800 million users, Twitter has about 500 million users. McKinsey & Company predicts as much as ~$1 trillion/year in productivity gains from the Web 2.0 "revolution," with anticipated productivity gains of up to 35 percent for some activities. Clay Shirky believes Web 2.0 radically lowers transaction costs, making fundamentally new methods of production feasible (for example, the volunteer community that builds/edits Wikipedia).