- 1. You can use subsonic as a 'product' for free. The trial version gives you enough access to get it up and running and test it in a browser, but with no API access, it's basically unusable for the primary use case (listening on mobile).
2. You can pay a monthly fee to use subsonic as a service. This gives you access to some additional features, including a readable web address, video streaming, dlna/casting to devices, and API access.
3. You can buy a lifetime subscription for $99. This gives you the same premium access, but lets you pay for it upfront. (Although let's be honest, $99 is a lot.)
Basically, I think it would be worth having a middle tier. There should be some viable way to use subsonic for a nominal one time fee. Really, a one time price makes more sense than a subscription fee anyway, I mean, what service are users actually receiving? The web address I guess? - Well I can do without that feature for a lower price. So what would be a reasonable price be for access to everything the free version gets you + API access? Personally, I'd wager somewhere from $15-$40, certainly I'd probably be willing to pay somewhere in that range.
Or is there another reason for using the subscription model that I'm not aware of?