Just to answer this... RSS feeds are meant to be updated they come and go. If the RSS feeds you offer are constantly changing and sites using them purge the old data that's fine. Why do you think all those Amazon affiliate sites took a hit this year? Duplicate RSS content....
hmmm...Offering my visitors their choice of relevant feeds is a negative...Thats a new one I think I now know who you are. Those two quotes give you away...Get lost and stop following me around. Don't you have something better to do with your time?