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CMDI’s merge/purge services improve the targeting of your fundraising efforts by cleaning and maintaining accurate lists. Keeping your lists in good shape helps your organization cut costs, reduce waste, and save time. On average, Account Services reliably processes over 10 million records per prospect merge/purge job.

What is merge/purge?

Merge/purge is the process of combining two or more files in order to identify and remove duplicates and unwanted donors. This strategic service produces the best possible list of names to contact for mail, email, advertising, or get-out-the-vote efforts. This service cuts your costs and reduces waste because you are only sending one piece to each targeted person.

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Why merge/purge your data?

  • Deliver consistent messaging to each prospect or donor.
  • Track how donors and files perform for future mailings.
  • Accurately test segments to see what works best for your organization.
  • Eliminate duplicate records and save on mailing.
  • Remove current donors, those you don’t want to solicit, and records that won’t provide results.

How does the merge/purge process work?

CMDI starts the merge/purge with all of the lists and files the client has rented, purchased, or created. If the goal is to acquire new donors, the client will normally use a house file as a suppression. People who requested to be removed during previous mailings are also suppressed.

Lists are coded in order to track their performance. Duplicates are usually coded with a separate multi-buyer code for a second drop occurring about 30 days later. Both the client and list brokers are provided with reports that show the number of names remaining after the merge/purge, along with the following:

  • Purge drops — matches to the suppression files
  • Multi-drops — duplication between input files
  • Single drops — duplication within the same file

How does merge/purge clean up lists?

Merge/purges can be run three different ways:

  • Individual – one mail piece is sent to every individual in the file. Lists are de-duped using first name, last name, and address.
  • Household – one mail piece is sent to the head of household. Lists are de-duped by last name and address.
  • Residential – one mail piece is sent to each residence in the file. Lists are de-duped using the address regardless of last name.

How long does merge/purge take?

Within 48 hours of receiving a request and all data, CMDI’s efficient merge/purge process is typically complete. All submitted data is standardized, duplicate records eliminated, and existing donors suppressed.

How to ensure your data is accurate & standardized?

According to the U.S. Census, nearly 36 million Americans move each year, which makes it difficult to maintain a high quality mailing list. CMDI recommends running your list through two national databases that standardize your data and update information for people who have moved:

  • Coding Accuracy Support System — The CASS certification process standardizes addresses for a better match rate according to best practices from the mailing industry. CASS improves the accuracy of postal codes, 5-digit ZIP Code®, ZIP + 4®, delivery point (DPCs), and carrier route codes. CMDI’s CASS Certification is renewed annually to meet current U.S. Postal Service requirements.
  • National Change of Address — CMDI offers 18 and 48-month NCOA processes.

The following trademarks are owned by the United States Postal Service®: USPS®, NCOALink™, CASS™, CASS Certified™. CMDI is a non-exclusive Limited Service Provider Licensee of the United States Postal Services®. The pricing for NCOALink™ Services are not established, controlled, or approved by the United States Postal Service®.


What data enhancement services does CMDI offer?

In addition to merge/purge services, CMDI provides other data services that add to the accuracy of your mailing lists:

  • Apartment Append
  • Bankruptcy Suppression — identifies individuals who have filed for either Chapter 7 or Chapter 13 bankruptcy
  • Congressional District Append
  • Deceased Suppression
  • DMA Mail Preference — identifies individuals who have requested to be removed from unsolicited mailings
  • DSF2 — helps to reduce the amount of undeliverable-as-addressed (UAA) pieces
  • GeoCoding — appends latitude and longitude information to data
  • Nursing Home Suppression
  • Proprietary Change of Address
  • Phone Append and Verify
  • Prison Suppression
  • Reverse Phone Append