Stock market live blog: Sharply lower; S&P, Dow see biggest monthly loss since …

Stock market live blog: Sharply lower; S&P, Dow see biggest monthly loss since …
While we're on the subject of Europe, a lot of investors piled into the Continent in the latter half of last year on ideas the U.S. rally was getting frothy. While U.S. stocks actually kept moving … But potentially bad news for Amazon customers …
Read more on MarketWatch (blog)

The rise and fall (and rise) of the billion-dollar social network
As Gladwell suggested, any idea, trend or company could “spread like wildfire” once it reaches a tipping point. As a result, online social networks now race to add users by “infecting” them with an idea and then giving them multiple ways of sharing …
Read more on Washington Post (blog)