How many times over should you pay?

In the real world, users prefer the notion of the perpetual licence, which works in exactly the same way as when a consumer buys a book, a CD or a DVD. You pay a one-time fee, and you can replay the contents for your own private use as often as you like. Of course, music publishers are starting to devise fiendish tricks to thwart that basic principle. The first step was discovering that consumers can be persuaded to adopt a new playback medium every few years or so, necessitating the repurchase of their entire back catalog on the new format. As David Berlind has been explaining in several recent blog posts, the latest wheeze is the use of digital restrictions management (DRM) technology to erect artificial barriers between different format generations (or even contemporaneous implementations by different vendors). Heaven forbid that home networking should thwart the music and movie industries' strategy of forcing consumers to rebuy exactly the same content with the emergence of each new format generation.

But the software industry is greedy enough to want to go even further. Ignoring the subtleties of DRM - which snares users by glossing over the unseen ties between content and format - vendors from BEA to Microsoft are eager to take up the blunt cudgel of subscription licensing, which merely asserts that, if you don't pay up again at the end of the year, your software stops working. The best way to deploy the mechanism of subscription licensing, of course, is as a hosted service, because it gives the software vendor the ability to instantly turn off the software-on-tap if the renewal is not forthcoming. Perhaps this explains Microsoft's new-found attraction to 'hosted everything' (whether or not it can work).