Streams would be for demos of the game, or for playing while your download finishes up.
While it’s a really cool idea, the streaming of videogames just doesn’t work as well as it needs to. Video quality isn’t up to snuff, you can’t play offline and, of course, the dreaded lag that makes some games just plain awful to play.
GameStop’s approach, which is set to launch in the summer of 2013, is a little bit different. If you want to get a feel for what a game is like, you’ll be able to stream the first 15 minutes or so. If you choose to buy it, you’ll start downloading it, while still being able to play the game streaming. Once the download is finished, you can launch it locally.
The service was initially aimed at PCs and tablets, but has since been focused to PC only.
Source: Venture Beat