The answer is 3 years of music enjoyment.
Honestly, this seems like a terrible example - I don't think anybody pays for spotify on the basis that they will have the music forever, it's very explicitly a rental service. Instead, people pay because it's the most convenient (including being cheap) way to access the music they want.
> While I'm not a CD junkie, I find myself clinging to the model you mention, because I am not eager to hand over control to a company that continually required me to pay
This doesn't really make sense either. If you don't like rental services, don't pay for them, buy the albums just like you always did - it's easy to buy DRM free mp3s nowadays.
> but it certainly isn't cheap
I'll admit, I was speaking more from the perspective of listening to a lot of music. For instance, the combined purchase value of all the albums in my spotify playlists far exceeds the total amount I ever spent on spotify, though I haven't used it for a while. I'm sure there are many people for whom this is true, even if they aren't a large proportion of the whole population.
In general you're right of course, 'cheap' is a matter of perspective. Spotify is not cheap for everyone, but it is potentially cheap for plenty of people. I still don't see the problem with this.
And, too, the collaborative experience that Spotify brings. I neglected to consider that. While very little money goes to the artists, the "sharing" aspect of Spotify is something that many people value and gladly pay for. Personally, I find that aspect too involved (I'm an albums person, not a playlist person) but from a marketing perspective this might be better for artists than physical media. I'm still too possessive for the rent-a-song method. What happened when I sign on and the music I like it out of license? Much better for me to have it as near to me as possible.
What prevents someone from doing the same thing with Spotify? Play music on one device, record it on another using audio patch cables if needed. Or maybe it isn't even that hard, just record the audio signal right out of the audio card in your PC. Is this prevented somehow?