It is fairly obvious to me why FB believes WhatsApp is worth this extraordinary sum.
The application is inherently social. Obviously, it is a texting/sms/chat whatever you want to call it, application.
a) I read somewhere that they (WhatsApp) add 1,000,000 users a month.
b) They have group chat.
c) They have grown by 200% YoY iirc
d) Their execution on the engineering side has been great
e) The ubiquity of the application and the execution of their marketing efforts, no manner how small, have worked tremendously and they know how to replicate that effect.
If those five things are not the impetus for establishing a serious competitor to FB I do not know what is. 19bln to fend off what could become a serious competitor is a pretty sound strategic maneuver. Especially since FB revenue per user of the platform is around $4.00 - $6.00. Add 400,000,000 more users to the platform and you bolster the power of the FB brand, get more ads in front of 400mln users and expand your reach into unpenetrated markets that do not have internet access reliable enough to use facebook. App or otherwise this is a great step for the WhatsApp team. They sure didn't get it for a discount but the potential consequences of letting WhatsApp keep getting users and not addressing that directly would have been rather risky.
There is my armchair analysis.
