I am trying to help a friend who is having a site developed to sell online downloadable products. Just a few products for now, no more than 5. The problem: what is the best way to have the customer pay online for the product, then be able to download the product instantly. Are there specific shopping carts that do this? Or are there sites that do this? Looking for the best (and cheapest, of course) way to accomplish this. The thing is to let the customer download the product but then make the link non-functional. I am not sure how to do this for sure. Any suggestions or help would be appreciated. Thank in advance for the help.