When I use to have a gamefly account, I would loose 3 out of every 5 disks in transit (had something like 30 games not show up over the 5 years I had an account). I would get ripped open envelopes that were taped shut.. I had cut open ones show up. I had one envelope show up so badly mangled they put it inside another envelope. ALL of them had the disks missing.. sometimes I would get the empty game holding envelope.
I looked into the transfer route after the first few are missing.. Gamefly center -> receiving office -> transfer location 1 -> transfer location 2 -> local post office
The post office tried to tell me that is was AFTER the mail was delivered that the thefts happened. I had a PO Box... so that still tells me it is within the system they went missing.
When gamefly went to the current packaging, the missing disk numbers did drop back to 1 in 10 or so. but when they did go missing, I would not even get an envelope in the mail.