This is a substantial gain from offering a presort program, and it accrues entirely to the mailers.
This doesn't work as well as a presort program, because it doesn't accrue to the mailers.
mnli hypothesis: This doesn't work as well as a presort program, because it doesn't accrue to the mailers. premise: This is a substantial gain from offering a presort program, and it accrues entirely to the mailers.