FYI Blog

Best Practices: What's a Merge/Purge?

We’ve all heard of a merge/purge and in general, know what this particular chunk of direct mail jargon means. But do you know how sophisticated the merge/purge process has become?

The Lists


Gone are the days when nonprofits borrowed or bought lists only from organizations with similar missions, mailed them, and hoped for the best.  These days, any nonprofit worth its salt takes advantage of the availability of lists way beyond its mission, because with today’s high-tech modeling and merge/purge operations, some of the financial risk of acquisition can be lowered before you’ve mailed a single piece.

Now, we can take in-house names of lapsed donors and activists, lists from like-minded organizations, mega co-op lists we’ve modeled against our own donors (to find the donors most likely to give), and other outside lists, to create a super list of prospects.


The Merge/Purge Process


Once we’ve collected all the lists, we run the merge/purge operation to merge the lists and purge the duplicate names. Those collected duplicates are donors who have given to more than one organization – multibuyers – whom we suspect are excellent donors. Also, since we’ve paid for those multibuyer names more than once, we can mail them more than once. So they’re coded separately.

We also suppress business addresses, foreign names, people in prison, and people who have registered as Do Not Mail with the Direct Marketing Association, as well as any of our current donors who happen to show up on outside lists because they give to other organizations.


The Importance of Data Hygiene


As part of our environmental stewardship, our goal is to always mail as accurately as possible – to save on postage, paper, and printing costs. So a critical part of the merge/purge process is scrupulous data hygiene – since each list owner manages his or her list in a different way with a different database and different standards of hygiene.


We start with the NCOA – the Post Office’s National Change of Address file, which runs USPS data against our merge/purge file. NCOA updates addresses of people who have moved, to make sure that each address is up to date and includes details like apartment numbers and ZIP+4, as well as purges deceased people. Updated addresses make the data easier for the merge house to work with, and also make it easier for the USPS to process the mail – all of which improves the quality of the mailing and its deliverability. The merge house will send back a file of address changes based on the NCOA data, so we can update our records. In fact, the USPS requires that an NCOA be performed at least every 90 days to qualify for nonprofit 3rd-class postage rates.


The merge house will also make the data uniform by running a USPS CASS program (Coding Accuracy Support System) so all of the addresses adhere to USPS standards, and we make all the address blocks upper/lowercase for readability. All this data hygiene helps the USPS sort and process your mail more quickly and easily, which ramps up the automation. Better automation means more heavily discounted postage rates and enhanced deliverability. Once the merge is complete, the merge house will split the file into control and test, and append source codes.


Bottom line: performing a complete and thorough merge/purge process means lower mail costs, a cleaner list, improved deliverability, and better response from new prospects – well worth the time and effort.