Thanks Bubbels.I hope too I like your idea about discount code(thanks) but I am not sure I've understood about advertising.What do you mean? Do you think I should get rid of product descriptions?Work on your product detail page. Getting the end user to add to cart is half the battle. I would consider removing the scrolling image area and place a larger image of the product on that screen. I would also format them all the same with the various elements. I would move the discount code to the checkout screen if possible. If not, at least put add to cart on its own line. You need that button big and with out question to what it does. The way it is now, I am probably going to go look for a discount code before I add anything to the cart.
Finally, get rid of the advertisement if at all possible. If its not an option, consider moving it to the right column.
Overally your site structure is well laid out, and I like the design. Fine tune that flow to checkout and I think you would be in good shape!