Does Marketpress upload a media file seperate every time someone buys a digital download?

Hello!
Does Marketpress upload a media file seperate every time someone buys a digital download? In other words, if we sell 3 sales and each file is 500meg, will market press upload the file and create a separate download url for the customers? I know that it does create separate urls but do not know if we sell a few, will it have to upload the file that many times using more space on the server?
thanks in advance!