The Co-founder of messaging app WhatsApp, Brian Acton, was rejected by social media giant Facebook for a job in 2009. Acton was also rejected by Twitter in the same year. On February 24, 2009, Brian Acton and Jan Koum, both former employees of Yahoo, incorporated WhatsApp. In 2014, Facebook purchased WhatsApp for $19 billion, making both the Co-founders billionaires.