Amazon launches today its Amazon Video on Demand service, which will enable customers to watch any of 40,000 movies and television programs immediately after ordering them, through video streaming technology. The advantage is that the file does not need to be fully downloaded to the computer, which is the case with similar services such as Apple iTunes and the original incarnation of Amazon’s video store.

Amazon has struck a deal with Sony to make its service available through a device called the Sony Bravia Internet Video link, a $300 tower-shaped device which provides Web videos to the company's high-definition television sets. Today's launch involves a limited number of invited Amazon.com customers, and the service will launch later this summer for the open public. Both Disney and ABC content are not available.

Amazon's idea is pretty cool, however there are a lot of competitors, some of which are pretty strong: Apple and its iTunes has a a strong fan base, and Netflix offers better image quality. Overall, the strong competition will certainly benefit customers.

I expect that in a year or so things will be clearer for the future of online video services, and the losers and winners will be easily discerned. Right now, it's hard to predict how the market will react to the multiple technological offerings and sales models.