this reminds of a recent episode of Silicon Valley, the eccentric billionaire Hanneman says, "If you show revenue, people will ask how much, and it will never be enough, It’s not about how much you earn but what you’re worth.....”
Initially i didn't see the sense in the Whatsapp acquisition, i think it was purely defensive, as well as the data FB could get their hands on.
"For all phone types, WhatsApp is free to download and try for the first year. After, you have the option of extending your subscription for $0.99 USD per year." from http://s831.us/1JbKMiG
pretty irrelevant. FB is a publicly traded company, and as such, it's pretty easy to see how much a social user is 'worth' in revenue terms. Instagram turned on ads, and so will whatsapp, perhaps. but ya, we have a pretty good understanding what social users are worth when monetized by social ads. And the value is influenced by future growth.