What music is really worth?

Boing Boing: Napster-to-Go reviewed, math done

Another aspect of the Napster to Go model is that it shows that the RIAAs claims of a lost sale for every download to be demonstrably false. If you can download an unlimited number of songs via napster and play them for as long as you continue to subscribe, then the maximum loss the RIAA suffers from a single downloader cannot exceed $15/month no matter how many songs a person downloads.

So, generously assuming a music listening lifespan of $80 years, the maximum lifetime value of a customer is 80 years * 12 months/ year * $15/month = $14,400