I've thinking about re-designing where my "add to cart" buttons go and wanted some opinions. Since I have a lot of content in the details page of each product, most descriptions extend beyond "the fold". So I currently have an "Add to Cart" button at the very top and at the very bottom. I can't place the button within the content itself due to database limitations.
One idea is to use a JavaScripts that always places the "Add to Cart button" on the upper right part of the screen. When you scroll, the button follows you and stays on the upper right. Is this annoying? Or would it help with sales you think?