The merge/ purge process is one of the most important data processing functions a direct marketing organisation undertakes. It’s obvious with rising paper, postage and list costs that there’s never been a more important time to make sure you’re getting the most out of your merge/ purge and list work.

The process of merge/ purge—bringing all of the files together for a mailing or series of mailings and eliminating the duplicates between lists—is designed to create a marketing list that has as few duplicates and is as clean as possible. The merge/ purge is necessary because so often mailers rely on similar lists to build their own houseflies, and frankly, to address internal hygiene issues that often plague direct marketing organisations.

A children’s charity, for instance, might swap and mail the donor lists of the Children’s Cancer Institute, the Children’s Hospital at Westmead and the Children’s Medical Research Institute. It would be reasonable to expect that the donor profile of these lists would be similar and, therefore, that there might be some duplication among these files. In addition, a housefile may contain duplicates as a result of existing donors getting new donor numbers with online website donations that create a false “new” donor. The merge/ purge is meant to remove as many of these duplicates as possible, and provide a unique set of records for mailing.

Most small to mid-sized charity direct marketers, and many of the proverbial “big charities” have their data processed by third-party service providers that specialise in the merge/ purge process as well as other standard database and hygiene services, such as NCOA relocation appends and TABR deceased suppression file processing. Work with your service provider to apply the following five tips to get the most out of your merge/ purge.

Five tips for getting the most out of your merge/ purge

1. Segment as much as you can while maintaining measurable cell sizes.
 Short of applying statistics for valid and reliable segment sizes, you can apply the Rule of 100s to setting cell sizes. This rule essentially suggests that to get a meaningful and repeatable result from a segment, you would like to be able to get 100 single cash gift donations for that segment. This means that if you expect a 2 percent response from a segment, you would need to mail at least 5,000 names in that segment.

In the merge/ purge, this is important because mailers often find themselves in need of splitting or nth-ing segments at the end of a merge to meet mail quantity specifications. If you find yourself in this position, and you have applied as extensive segmentation as possible, allow yourself greater flexibility by selecting inclusion records on the back end. Instead of having to nth from a set of 30,000 36-month donors, leave yourself the option of selecting for a subset of 12,000 36-month multi-donors.

2. Use different merge rules for business and consumer segments.
 Merge rules are a set of instructions that dictate whether duplicates are to be matched at the individual level (e.g., same individual at the same address), at the household level (e.g., same surname at the same address) or at the address level (e.g., same address regardless of name). Each set of rules defines what is or is not considered a duplicate.

Most service providers will allow you to assign different rule sets to consumer records and business records, as well as to enhance those rules with special instructions. An example would be to allow the merge to mail multiple records to a business site but only one per family household within a single processing run. By assigning different rules, you cut down on processing costs and allow the right mail strategy to align with the right segments in your file.

3. Bring in more names than you need.
 This tip applies to both housefile segments and prospect lists. As mentioned above, there often are mail quantity specifications that are set prior to going into the merge/ purge. Printer contracts have been signed that guarantee a specific mail volume. In addition, you may be testing new lists or new segments within proven lists in search of new opportunities to grow your file. List order minimums often are 5,000 names and frequently, these are the test order quantities that mailers opt for. However, you should consider the impact on quantities in the merge/ purge.

Every mailer that is a member of the Association of Data-driven Marketing & Advertising (ADMA) or the New Zealand Marketing Association (NZMA) should run all outside lists against the ADMA or the NZMA’s National Do Not Mail files. When you do that, you may be surprised how many names from your prospect lists will match that file and, as a result, not be included in the mailing. Also, consider the Rule of 100s mentioned earlier, and couple that with the fact that many mailers realise response rates from prospect lists in the range of 0.8 percent to 1.5 percent. Given these points, if you want to get 100 responses from a prospect list at a 0.8 percent conservative response rate, you need to mail 12,500 names. Now consider the effects of the merge, where you may lose 10 percent of a list to duplicates and Do Not Mail matches. You would need to bring about 13,850 names into the merge/purge to get the 12,500 names you want to mail. Said another way, if you order 5,000 names (the typical order minimum) you may only get 4,000 in the mail which, on a good day, might produce 48 new single cash gift donors —not much to learn from.

4. Go random in the merge with prospect lists.
 There are varying opinions about how to treat prospect list hierarchy in the merge/ purge. Some mailers take the position that all swap/ exchange lists should be ranked higher than co-operative database lists, which would rank above any pure rental files. This approach is better for managing costs, particularly when net-name arrangements are put in place for rented lists.

Another approach, however, is to allow all prospect lists to rank the same in the merge/ purge, a concept known as going “random in the merge.” Allowing all outside lists to go random in the merge gives each list the opportunity to “keep” the better multi-list names. In this way, the post analysis can provide an apples-to-apples comparison of list performance. Unless you are a large mailer, you’re probably not yet in the position of finding purely incremental names. For your organisation, finding new list opportunities still is critical to growth, and allowing lists to go random in the merge gives the greatest opportunity for finding new lists that work for your offer.

5. Make multis a part of your mail plan.
 Multis, or multi-list prospects are names that show up on more than one outside list. If, for example, Jane Smith records showed up on four outside lists that you rented for a given mailing and she wasn’t already on your donor file, she would be referred to as a “four-time multi.” These multi-donors generally are strong responding, highly qualified prospects—in other words, the best possible prospects you can get.

Many mailers deal with these records as an afterthought, if they deal with them at all. But to get the most of your prospect lists, make multis a part of the mail plan by evaluating past merge/ purge results and estimating how many multis you will have available after processing. Include these names in earlier and later drops than your main prospecting drop. The key is that when you plan to include them, they can make a significant impact on revenue and new donor acquisition, and may even outperform older house segments.

Bonus Tip 

• Manage your super-dupes. Super-dupes are hits between your older housefile and prospect list. Consider test mailing the matches between your older 36- and 48-month donors and outside prospect files. These records typically perform very well.

The merge/ purge is more than just a quick de-dupe. To get the most out of it, use all available tools and plan in advance. The more you plan, the more you will get out of your next merge/ purge.