Is this site intended to compete with and eventually replace reddit and facebook type sites? If so then there are other ways to do this. Filters, channels, etc. If such artificial restrictions are placed it will work for probably a lot of people, but the thing about social networking is the more that people use it the more they like to share. Do we want to penalize them for that? If we're talking advertisements and posting the same post over and over that is spam. Beyond that the term SPAM becomes a very subjective thing. Though we CAN always try it out and see what happens before we say.... BAH this won't work. It can be rolled back if it doesn't work out, I am sure.