Films and 'shareware'

So Monday's discussion on piracy got me thinking about ways in which the film industry could face up to its issues surrounding piracy. The best I could come up with is based on what the video game industry did during the 1990s where they would release a portion of their product as 'shareware'. Basically the premise was that a limited amount of the games content was freely available - note this was before the internet took off so it involved the copying of content on floppy discs and early CDs. For example the game Wolfenstein 3D contained 6 episodes, the first of which was deemed shareware. Gamers could replay the first episode as many times as they liked, they could also give copies to friends legally. If however gamers wished to play the remainder of the game the next 5 episodes needed to be purchased. Films could adapt this concept and make say the first 20 minutes of films freely available, likely from a large central database. Consumers would need to purchase the remainder of the film if they wished to see it to the end, if they decided that after 20 minutes this particular film was not to their tastes they could simply stop right there, or alternatively share it with friends that might enjoy it. Books also sometimes include this model, by sharing the first chapter of upcoming releases online in order to generate a buzz about the title. I doubt this concept would erase piracy altogether, as full versions of Wolfenstein were commonly pirated even back then but it could be a start.