Funnily enough, I hadn't even heard of the Million Dollar Homepage until users started mentioning it! The core concept is quite similar though, I do agree :) I think where I've differed a bit is more of the focus on community involvement in message value, with a weighted pricing + (free) discussion/reaction system. A lot of great feedback I got was around the potential for some high-priced message to just kill further interaction, which is similar to what happened once all the pixels were bought up on the homepage.