In my time at a label I tried to work with them, but their technology is kind of awful, so I wouldn't be shocked if Turntable is looking for a better partner.

Essentially they are a proxy between the label catalogs, reporting for royalties and DSP's (digital service providers) who license and distribute content.

Or as I referred to it internally, the "API Model"

Regarding the user uploaded stuff, that's under DMCA.

Of note: Turntable really falls into two licensing camps: DJ and listener. Very different terms required.

Most of the big public rooms are founded on playing pretty obscure stuff. The indie rock rooms could survive but the electro and dubstep type rooms would definitely die.

I have no idea what the usage patterns are (do most people hang out in big public rooms or small rooms with friends?) but a pretty big segment would complain if uploads went away.