As Intelisent notes, "Full Service requirements are both expensive and hard to handle. Managing the sequence numbers on the mailpieces is not all that difficult. However, Full Service also requires unique sequence numbers on the trays, sacks and pallets. Pallet placards must be affixed to the outside of pallet wrapping, which doesn't sound like much, but adds an adhesive expense and handling for the mail service preparer. And - if one of those placards falls off in transit and handling - poof, goodbye discount, downstream. This loss of discount would take place well after the mail has already been accepted." Read more!