Why should they be reduced? The viral communication only works because people trust each other. If you destroy the trust and willingness of people to cope with the constant spam of applications: people start to get stressed because they do not know how to react. That leads to people not using myspace at all. It is similar to the "no do" for POS in shops. If you over stimulate people already at the entrance with attention grabbing offers - they will buy significantly less and are more likely to not come again.
