Amazon has launched its video-on-demand service in the US, giving Mac or PC owners access to 40,000 movies and TV shows.

Called Amazon On Demand, the service lets users rent or buy videos via Sony's Internet Video Link Device on compatible Sony Bravia TVs. Alternatively, they can watch shows via their web browsers. A preview service, under which users can watch the first two minutes of a movie or TV show before deciding to buy or rent it, is also available.

"The ability to watch content instantly without downloading first was among the most requested features of our customers, and now it's live - customers can instantly watch the ad-free title of their choice on a Mac, PC or compatible Sony Bravia TV," said Roy Price, director of Amazon Video On Demand.