That link perfectly describes my concern with subscription systems. If Apple distribute the royalties calculated per-user rather than based on (total royalties / total number of listens system wide) I'll move over from spotify, as it will reward the bands I like more than the current system.

I like that spotify pays royalties from free accounts, I dislike that I am effectively subsidizing this as a premium user. However, at the moment I am more comfortable with this than apples '3 months no royalties' system.

Another interesting point is that for a music subscription services, there is very little keeping users tied to one provider - all I need is the ability to export my playlists. I wonder if spotify's revenue will collapse for 3 months, but if they can be better than apple, they can get it all back 3 months later.

You aren't subsidizing anything. You are paying market price for a product. The seller does bizdev how they choose.

Technically true. I think for the arts this is something of an unusual case I'd describe more as an emotional than a financial transaction. I'm paying for something that I could easily get (illegally) for free. My allegiance is to the music and musicians, not to apple, spotify or anyone else providing distribution, as such 'supporting the type of music I like' is a very strong selling point, (not strong enough for me to use Tidal though!)

I presume Apple are trying to establish differentiation through the 'radio' service, but since the baseline market requirement is the ability to listen to practically anything all-you-can-eat, it'll be hard for them to achieve it there.