There are 600 million people actively using WhatsApp. According to its founder, Jan Koum, the mobile app got 100 million more active users in just the last four months. Koum was quick to point out that active users are people using the app regularly. WhatsApp gained traction in every major region in the world. It's growing the fastest in Brazil, Russia and Mexico, and a tenth of the active users are from India. Facebook acquired WhatsApp at the beginning of this year for $19 billion. It expressed interests in monetizing WhatsApp better and is reportedly working on file sharing and call features. However, WhatsApp's most valuable part for Facebook is the database. Top traffic and the number of conversations allow Facebook to extract marketable information on the users' likings. Mark Zuckerberg said, "[WhatsApp] is the only app we've ever seen with higher engagement than Facebook itself." WhatsApp can also borrow what its competitor WeChat has been doing. WeChat took over the smartphone chatting arena in Asia by storm last year and it sells special stickers and emoticons for users to share with friends. Of course, WeChat contributes the most to its parent company Tencent's bottom line by driving traffic to everything else Tencent owns, and Facebook wants the same.