Facebook acquired the messaging app WhatsApp for approximately $19 billion, significantly outpacing other acquisitions like Viber. WhatsApp, which boasts over 450 million active users globally, operates on a subscription model of $1 per year after the first free year, distinguishing itself by avoiding ads and monetizing through user subscriptions. The acquisition raises questions about how Facebook will balance its monetization strategies while maintaining WhatsApp's independent model and data practices.