There has - unsurprisingly - been a great deal of internet chatter about the staggering $19 Billion which Facebook is paying for Whats App.
Is a messaging app worth $19 Billion? Of course not. There are many messaging apps, and if you paid a couple of developers more than $50k each to build a decent one you would certainly be cheated. I built a basic local messaging app for a 12-PC Northstar Horizon network, pre-internet, in 1984, and it took me just a few hours. Messaging is not rocket science!
What Facebook are paying for, of course, is a half-billion user base. One 14th of the planet.
But is half a billion users worth $19 Billion? Using standard-ish multiples, given a turnover of (very roughly) half a billion a year, you'd expect to pay $1 - 2 Billion for the business, but it goes without saying that a business with half a billion users is anything but standard.
But... how is Facebook going to make its money back (that's what investments are for, after all)? It remains to be seen whether Google, Microsoft, or someone else is going to start poaching dissatisfied users who resent the fact that their app is now property of Facebook.