The two ave also struck a deal to create original fact-based shows for both conventional TV and digital, complete with a dedicated team at BBC Studios. It's effectively a revival of an earlier alliance that produced shows like Planet Earth.

While the pact could help Discovery's service become a go-to destination for documentary fans, it also risks adding to the mounting issue of subscription fatigue. When customers have to sign up for an ever-growing number of streaming services to cover everything they want to watch, there's a chance they'll balk when there's one more added to the pile. That's particularly true if a service is taking control of content that used to be available through a catch-all provider like Netflix. There's no guarantee fans of BBC docs will follow the shows to their new home.