Facebook and YouTube are both in the market for users to show advertising to, and generally every minute spent on one is a minute explicitly not spent on the ot

Facebook and YouTube are both in the market for users to show advertising to, and generally every minute spent on one is a minute explicitly not spent on the other. If facebook were selling communication with friends, then YouTube would not be a competitor, but that's not Facebook's business, nor would anyone argue that Facebook has a monopoly on talking to your friends.