Contract with one of the coops to score your files after your merge is complete, to help identify unprofitable names that you can drop from your mailing.
Separate house and outside names when doing post-merge scoring, as you will likely drop more segments on the outside universe than you will on your house universe. Also, you have the option of dropping greater or fewer names by individual list.
Select house names that you would ordinarily not mail, and place them into your merge. Then, take the top 25 percent or 50 percent of the names after they are scored post-merge. You can also apply this strategy to outside lists. If you are already making a last 3-month hotline work on a particular list, try selecting a 4- to 6-month hotline on the same list, but only mail the top portion of the list once the names are scored after the merge. Make sure the economics work, as you will end up netting out very low. You can apply this method to mailing incremental model segments of the outside prospect names you are mailing from the coops, too. Try mailing only higher portions of a segment by dropping the lower portions after the merge.
Re-key and mail small portions of the segments of names that you are dropping, to prove that it really pays to drop these names. If the rekeyed names in segments 19 and 20 prove to be unprofitable, re-key segment 18 in the following mailing — and continue this strategy until you reach the point where it makes sense to stop. Always re-key house and outside names separately, as they will likely perform differently.