I'm sure there are use cases for this, but I see two issues I'd be worried about when using it.
First of all, any exclusivity requirements on any platform. Something like this must get you in trouble with the TOS of any of these sites.
Second, the culture of streaming on each platform is unique. Not to mention the form factor and expected behavior of any chats on each system. Or even things as simple as vertical vs horizontal video formats. Sure there are areas where this doesn't matter, there always are, but it shouldn't be ignored when trying to spread your reach.
Before you get partnered on Twitch. So before you average 100 viewers it won't really matter. So restream is good if you are starting out and want to try different platforms. It may be that you find a following on a different platform than what you thought you would.
Interacting with chats from 3 different platforms might be weird/hard though.
I got the impression that Restream is mostly used for talks / podcasts.
I know of DJs who use the service to hit YouTube, Facebook, Twitch, and maybe Mixcloud all at the same time. In that case, they're not trying to grow a platform-based audience (like gamers). They're simply trying to reach their existing audience through the available channels.
I don't think anyone is taking exclusivity seriously, except maybe well-paid gamers. It's too early to act like Apple. Maybe once live streaming matures...?
Twitch definitely cracked down on Restream usage among partners at some point in the past, because I used to watch some streams on YT and that stopped happening suddenly, with some of them citing their Twitch contracts.
The culture aspect is big, splitting a viewership base across multiple platforms makes it hard to do things like community building, on screen chat, etc fluidly. These are especially prudent for small streamers, much more important than being on every platform at once.
Quality over quantity.
I could see this being useful for brands though, where a live stream is pure marketing maybe.
The economics on this are confusing to me; if they’re hosting a “repeater”, they’re paying for bandwidth in/out, and that’s expensive.
If the streaming software is sending to multiple locations; the stability will be low (assuming folks become outbound b/w limited from their home conn).
Am I missing something obvious here?
At twitch we needed a heck of a lot of interconnecting with various providers to make our service viable.
A few other commenters seem to be confused about the purpose, so here's what we use Restream for: easily switching streaming destinations without reconfiguring our encoders (eg we use Twitch for informal student facing content, LinkedIn + FB + Periscope for content we want to be seen by professionals).
Honestly I was also initially skeptical of its utility but it turned out to be pretty worthwhile.
nginx-rtmp can take a source and forward to multiple outputs.
Fairly more advanced is BBC's Brave which is more of an API-driven live video editor that can push to multiple outputs.
This has been around for years. It's a solid service. With Mixer's FTL it added normal amounts of delay, so that kind of sucked, but no need to worry about that now, I guess.
First of all, any exclusivity requirements on any platform. Something like this must get you in trouble with the TOS of any of these sites.
Second, the culture of streaming on each platform is unique. Not to mention the form factor and expected behavior of any chats on each system. Or even things as simple as vertical vs horizontal video formats. Sure there are areas where this doesn't matter, there always are, but it shouldn't be ignored when trying to spread your reach.