By April, WhatsApp had crossed over the 500 million mark along with a new daily record of 64 billion messages handed in 24 hours, 20 billion of which were sent (inbound) and 44 billion received (outbound) by users. What that boils down to is an additional 100 million members in the course of four months.
Now serving 600,000,000 monthly active users. Yes, active and registered are very different types of numbers...— jan koum (@jankoum) August 25, 2014
There's a bit of snark in Koum's announcement, as competing services will often announce the number of registered users instead of revealing how many of those members are actively using the service. Koum leaves no doubt.
Image Source: Flickr (Sam Azgor)
The challenge Facebook now faces is turning its $19 billion investment into a money generator. WhatsApp currently charges members a mere $1 per year, and that's after giving away a free year of service. Advertising and games are two avenues Facebook could take, though Koum has been against both.