Facebook will buy WhatsApp for $16 billion in cash and shares, it announced today.
The hugely popular WhatsApp instant messaging (IM) service has almost half a billion (450m) monthly users, loved for its emoticons, instant picture sending and group messaging.
In fact, WhatsApp messaging volume is now almost equivalent the worlds texts (SMS) volume sent via telcos, and adds more than 1 million new users a day.
Compare this to Facebook, established in 2004 has 945 million active users, and the growth of WhatsApps is incredible, considering its less than 5 years old.
The move is another play by Facebook for the Internet users who are verging away from the original social network.
"WhatsApp is on a path to connect 1 billion people. The services that reach that milestone are all incredibly valuable," said Mark Zuckerberg, Facebook CEO.
"I've known Jan for a long time and I'm excited to partner with him and his team to make the world more open and connected."
It is not known if Facebook will look to change the IM service but said, WhatsApp's brand and 'core messaging ' will be maintained.
WhatsApp headquarters will remain in Mountain View, California, and co-founder and CEO Jan Koum will join Facebook's Board.
Koum said, "we're excited and honored to partner with Mark and Facebook as we continue to bring our product to more people around the world."
Facebook's own Messenger app will continue to operate, as normal.
It will also provide Whats App founder and staff $3 bn worth of additional Facebook restricted stock, which will be vested over four years, bringing the grand total Zuckerberg and Co. forked out, to $19 bn.
WhatsApp was co-founded by Jan Koum and Brian Acton, two former Yahoo! employees.