Who are shopto? They are an excellent site that offer games far cheaper then either Game or HMV - even new releases are cheaper. They also do next day free del. and send a text message to your phone for free when they have shipped the game.
I've ordered around 12 games from them over the last few years and I've been more then happy with the service and price - pre-oreders tend to come a day before the release date too.
I don't see why people wish to pay Game and HMV extra money simply as they are brick and mortar stores - I have a Game card but never use it now - if you don't buy from Shopto due at least buy games from Amazon.co.uk!
Why aren't people pre-ordering Kinect?
People who order from shopto are normally 1 - Informed Gamers 2- People looking for a bargain. It's also months away from release and consumers are waiting for more information before pledging money. I doubt many people will pre-order before an official price is announced. Anything more then £100 is going to take some selling.
Ps. GAME is good for trying out games if they have a demo setup and just for browsing whats on offer - check it out, try it out then go home and order online.