As an example, I think it'd be nice if eventually Spotify decided to offer wood-engraved machine-readable BitTorrent QR-code links to each of the albums you hav

As an example, I think it'd be nice if eventually Spotify decided to offer wood-engraved machine-readable BitTorrent QR-code links to each of the albums you have in your profile; effectively available in perpetuity and on-demand by placing them into an appropriate reader with cached storage and Internet connection -- no need for huge capacity in either of those. The engravings could be available on a large delayed timescale to provide for healthy forestation and materials gathering.