Deng, who led product for Facebook’s messenger product in the early 2010s, says he was not worried about WhatsApp growing into a big rival in the US. Since many people in the US had iPhones where they could send mobile messages including photos through iMessage, he says, “people just expected more here than just text messaging,” which was the focus of the simple WhatsApp service. “There’s nothing about what they did that signaled they remotely wanted to get into more expressive messaging.” he says.