Game demos have become de rigueur for publishers. To help entice gamers to plunk down their hard-earned US$50 or US$60, companies will often put a sample level from their games on their websites, Xbox Live or the PlayStation Network. Until now, those demos have remained static, meaning publishers effectively giveaway a chunk of their games in the hopes that it will lead to consumers scooping up the whole thing.

Sony, apparently, wants to change the demo paradigm. In a March 4 US Patent and Trademark Office filing uncovered by Siliconera, the company has patented the technology to make demos that lose functionality over time. The more a player plays the demo, the more features of the demo will cease working — and the more it will ask the player to buy the full version.

Read more of "Sony patents demos that 'erode'" on GameSpot.

Via CNET News.com