Copernicus,

The fact that these are the two systems in most common use today does not mean that they are the only two methods possible. You had a few suggestions offered in your own thread. There were at least two cases I know of (Datawiz and Sygic) who were selling software through Maemo repositories, an app "store" with no concept of a user account. Before Maemo, I bought some Palm OS software through sites like Handango, again with no user account. More in my comment in the TJC thread. Sorry, I have not worked out how to link to a specific comment, so I have to link to the whole thread.