Vimeo won’t “go down” anytime soon. It might get worse/more expensive, but it’s not in imminent danger. And it’s also not the only white-label provider around, either.

Bending Spoons also bought Brightcove so they actually own two of the white label streaming providers.

Would not be surprised to see the two merged into a single service.

For customer facing streaming sites they also don't seem to be the clear default choice. I think dropout.tv is one of the few "secondary streaming services" to still be with Vimeo (and with the strong overlap in their networks I'm sure they got a good deal), while many other ones like Nebula evaluated them but went with other providers.

It looks like the majority of their business is in employee training portals for megacorps.

The Nebula apps are pretty bad. Vimeo white label has issues but the app experience is much better than whomever Nebula are using.

One reason Vimeo is a good deal is that they charge for video transcoding by the minute, not by the file size. So you can upload full ProRes 4K movies and it doesn't cost the earth.

I dug in a bit and did a little research. Criterion and Dropout, as mentioned, use Vimeo. So does Arrow's streaming service (cult films, mostly). From there on in it gets even more fringe: Taskmaster (the British game show) has a streaming service built on Vimeo, the Z-movie titans Troma and Full Moon Features use Vimeo, and so on. So not insanely crucial but I still think it's a better world in which those services can keep doing what they do.

Yes, there are alternatives. Nonetheless, the niche streamers I'm thinking of would find it a moderate burden to move to a different provider and they're operating on slim margins as is.