Ask HN: How are big players handling large number of live video broadcasts?

Periscope. According to an article from medium [1] Periscope had a peak of around half million daily broadcasts. This may mean that Periscope have handled many live broadcasts to tens of thousands of users simultaneously!

Here I can imagine some complex hybrid P2P and TURN server with regional load-balancing and limiting content exposed to users may do the trick for handling the traffic. But this will come with expensive cost.

So my question is, from point of view of a start-up which has a similar problem of scaling as traffic grows, how would you implement your handling of this traffic?

P.S I understand you may say start-up project with 10 live broadcasts would be a dream! So I will clarify, how do you gradually move so if the project is successful you can handle the traffic with minimized costs on bootstrap?

[1] https://medium.com/@somospostpc/how-many-periscope-broadcasts-are-made-daily-808ae7f32de#.w2tltjeul