Postal: Help USPS Help You
These fill-ins usually fall within the spoilage allowance of the print quantity, so the mailer will not need to print any more pieces than necessary. The additional postage cost is usually less than the difference in postage savings, meaning a net reduction in postage even though the mailer is mailing—and prospecting—more.
A marketer can apply the same technique with a name list; however, the costs of such lists run significantly higher than Resident/Occupant files.
Another thing to consider about list density: The denser the mailing list, the better the postal delivery performance both in speed and consistency. But here shape matters greatly. With letter-size mailings, it is not quite as simple to earn 5-digit automation as it is with ECR qualification. The same approach may be taken. But instead of the 10 pieces that flats require for ECR qualification, letters may need as many as 150 pieces to qualify.
Fill-in prospecting can still be achieved with letters, but may require using a presort service bureau or commingling services to earn the discount collectively with other mailers (more on service bureaus below).
Compared to presort, USPS automation discount requirements are far more numerous and strict. Mail pieces must be able to be run at high speeds on postal automation equipment and need to be pre-barcoded.
In this environment, the carrier does not rule. The machine scheme employed by the postal service to sort, or "case," the mail is most important. There also are Move Update requirements to assure the piece is going to the correct person at the appropriate household so the USPS does not have to further process the mail. Letter mail is incentivized to be automated, rather than carrier route presorted, because the USPS desires to machine case all letters.
It is more difficult to add addresses to a letter mailing to achieve 5-digit automation due to the quantities involved. However, this is where a presort service bureau or commingling comes into play. These allow several mailings to be combined to earn deeper automation discounts, and they aid in building deeper pallets for Sectional Center Facilities where letters are processed.