The magic of merge/purge

DM News. 2/22/2007

Merge/purge. It’s that mysterious process that occurs between list purchase and mailing. Merge/purges ensure that we marketers don’t waste our clients’ money by mailing to duplicate names, to duplicate households or to current customers or members.

But did you know that the merge/purge -- otherwise thought of as a tactical part of a direct mail program -- can actually play a strategic role? Here are two ways.

How we conduct a merge/purge can impact audience potential.

If a match is performed at a household level only, an individual in a household where another household member is a current customer will match the customer suppress file and be eliminated.

If the product or service offered is one that can be bought by multiple individual household members, this approach eliminates some portion of the prospect audience.

However, merge/purges done on an individual level first and then on a residential level will preserve these prospects, while still resulting in a mailing file that directs mail to one individual at each residence.

If, though, the mailing is a one-step program with an application or order form enclosed, the additional postage and production costs to mail more than one to a household may be acceptable.

The output of a merge/purge is in actuality a series of reports that can reveal which lists are likely to perform better.

A standard merge/purge report summarizes how the random assignment of duplicates resulted in the output quantity for each input list. Looking at the percentage of single buyers (records that matched no other record) allows a marketer to assess which lists had little in common with the other input files and with current customers.

An additional report (sometimes called the matrix) is a much more detailed report that analyzes each list’s level of duplication with every other input and suppress file, including customer suppress file.

In general, those files with a high level of duplication to the current customer file perform well, while those with low rates of duplication tend to not do as well. Sophisticated marketers will consult both of these reports to project which lists have the most potential for success.

Who would have thought that a merge/purge report could be so telling about potential mailing results?