More "missing packages" are due to buyers misplacing a package or deciding to disclaim receipt than are lost by the carrier. If you are shipping something of some value to someone you don't know, particularly if not a club member, insure for your own protection. The USPS insurance is higher than it should be based on their loss record for 1st class mail and you should only buy it if you have some reason to mistrust the buyer or if the loss would be financially painful to you.