WhatsApp initially gained traction among its initial users by offering its service for free in early 2009. This allowed the app to spread quickly due to its simple and intuitive user interface, and its ability to send and receive instant messages, images, and audio recordings. Additionally, WhatsApp had a low barrier to entry, promoting its compatibility with iPhone, Android, and Blackberry platforms. Its convenient registration with a user’s existing mobile phone number also allowed existing users to quickly and easily add the app to their device.