PM's are used in the resolution center. For example a customer may agree to some terms and conditions that a vendor has given him via PM before a purchase. Or a vendor may make a promise via PM. All these things are looked at and considered when a resolution is decided. I do agree that messages shouldnt be kept in the database longer than required.. I think (i only mod the forums and have nothing to do with design) perhaps they should be deleted if they are all read & after any transactions with the vendor are finalized. Or just a on a timer.. so all messages are deleted from the database after 30days..