I love the idea, but besides the retrieval fees involved that you're not disclosing, I wonder if people will grasp the fact that the files they are putting into the icebox folder are not reachable with opening the same folder and looking into it—instead you need to go to a web site to find them. This is rather disorienting for a non-technical user as the way of putting files in gives a false sense of immediacy to a future retrieval availability.