How does whatsapp make its money? And how much has it made and how much is it worth?

In February 2014, social media giant Facebook paid $19 billion for WhatsApp in cash and stock. There are currently around 450 million WhatsApp users.

For all phone kinds, WhatsApp is free to download and try for the first year. After, you have the choice of extending your subscription for $0.99 USD per year. Subscriptions are increasing, so if you pay for an additional year of service, it will add to your current subscription or free year-long trial. There is no difference between the paid and free versions of WhatsApp other than the length of service.

WhatsApp is available for Android, iPhone, BlackBerry, Nokia S40, Symbian, and Windows Phone.

If you're wondering why they charge instead of offering the WhatsApp for free as an ad-supported app, they explain it like this:

Their 2 programmers worked at Yahoo! for a combined 20 years, and saw the wasted time spent tuning back-end software to serve ads; time that could be better used improving the application itself. As well, they wanted to offer the best user experience that they could, and not ruin the aesthetics of their software with ads, thus they chose the paid approach instead. You can read their entire blog post on their reasoning here.

Business Insider offers 10 tips and tricks to consider before downloading Whatsapp on to your phone.

Updated on Saturday, September 06 2014 at 10:13AM BST