Well, for one, if I know it is a quote invented by the person submitting it, I immediately down vote it, no matter what. I realize there are a few decent self-quotes here, but if this site eliminated ALL self quotes, then the quality of the material on this site would sky rocket. I would gladly wade through the occasional tedious Meyer or Dessen quote if I didn't have to get bogged down with the shallow, tedious, trite, and/or grammatical train-wrecks that almost all these self-quotes are.
OR: If, at the least, once I downvote a quote, if it would never appear for me again, that would be bliss.