If you elect to queue a demo from Xbox.com on your browser, and you aren't logged into Xbox.com on that device, you run the risk of accidentally buying the content instead of trying it out, as pointed out by a Giant Bomb user.
That's because after you click the "Try Game" button and log in, the system acts as if you've elected to buy, giving you a "Confirm Purchase" button. If you aren't paying attention, and you just click through, you'll have made the purchase.
Luckily, Microsoft told Giant Bomb that the web team is aware of the problem, and is "actively working to resolve it." In the meantime, read every button!
