MyItemTracker tracks the price of products found on Amazon. We are likely to add more stores in the future so logo should not be Amazon specific. You can track any item and enter your target price, if the product becomes available at that price we will notify you.
Consumers who browse Amazon for products
Logo for header. Should be no more than 950px wide [the size of the white area on the page].
Creating a background as well to go outside the white area [where the dark blue area is now] will increase your chances of winning.
As far as design, be creative. Do not use any unlicensed or royalty based graphics.