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.