Outside of the US WhatsApp rules with an iron fist. Every non-tech person I know uses it. I hear it dropped in casual conversation at the table next to me in restaurants. It's got a public mindshare greater than Skype. And once all your friends are on it, it's not so easy to switch.
I can definitely confirm this, at least in The Netherlands literally everybody uses Whatsapp and it has slowly become a verb - "I'll whatsapp you the details!".
It's far from the best messaging app, but definitely the most popular (in Europe).
India too...( where whatsapp adoption spread virally from blackberry, symbian, etc first and smartphones later)
i work on an im client[1], and my mom sent me a link about whatsapp :)
[1] to be fair, verbs.im is a gtalk/aol/yahoo multi-protocol client. infact, one day we could wrap over whatsapp as well. not exactly re-building a new graph but re-using your existing lists.
Pretty fascinating reading the comments here about how big WhatsApp is outside of the US. I've never encountered anybody using it here, never would have guessed it's so popular elsewhere that it's been turned into a verb.
I think this is a great example of why you should never be afraid to try and reinvent something. Even a concept as simple as messaging apparently still had a (potential) billion dollar opportunity.
