The messaging s...

The messaging service [WhatsApp], founded in 2009, has been so successful because it understood from the start the importance of embracing mobile technology. That's something Facebook struggled with, notably going public without any revenue from mobile devices. Facebook now gets more than half of its revenue from advertising on smartphones and tablets, but it still is looking to expand its mobile reach.

On the $19 billion price tag of Facebook's latest acquisition.  Via CNN.