Finally, WhatsApp might have earned enough money that WhatsApp founder Jan Koum announced on Monday 18th Jan. 2016 that they are going to remove the annual membership fee and WhatsApp Messenger will be free forever from now. Charges will be dropped to free immediately but we will see the changes in upcoming updates of the WhatsApp Messenger. So there will not be any fees after completion one year and no need to worry about losing contact with your loved ones.
Rumors says that WhatsApp has taken this decision as Google is coming with their own social chat app to compete Whatsapp and other Messenger applications, etc.
Whatsoever the reason for making WhatsApp free, but now people can chat for free and enjoy the upcoming features of WhatsApp for free.
Source : WhatApp Blog