https://techcrunch.com/2020/01/06/amazons-fire-tv-platform-now-reaches-over-40-million-users-topping/

Amazon’s Fire TV platform now has over 40 million users, the company announced today. That’s up from the 34 million it claimed in May 2019 and more than the 32.3 million active accounts Roku reported during its Q3 2019 results this past November.

Roku’s “active accounts” figure describes those accounts where users have streamed at least once during the past 30 days, but Roku notes that one Roku account may be shared by multiple members of the same household. However, the same can be said for Fire TV which, like Roku, doesn’t offer an easy interface for switching between different user profiles in order to create a personalized home screen or watch list.