From their email: "You'll need a credit/debit card to download games. All games are still free to try. Your card will only be charged if you buy content you love. We do want valid payment information for everyone. This is to ensure that game developers can get paid when you love their game."
The article mention gift card, but I just don't want to pay a gift card that I may not use just to download demos. Well I guess I'll use the hardware as a MAME box, and video player.