If Spotify were $50 a month it'd still be worth it. I don't know how they divvy up profits but lets look at this example:

I pay $12 a month and only listen to one record three times through on that month. You'd expect the artist(s) of the record to get my $12 minus a service fee, but what I'm sure happens is the artist(s) only get the price per play x 3 and Spotify pocket the rest.

Subscription models are a huge boon for this reason, but the inequitable split might change artists' minds about these sub services.

I tend to listen to a small subset of music over and over, the artists should be getting close to that $12/month cost in my opinion.