The Marketer’s Guide to Suppression Files

A suppression file is a list of records you identify and remove from a contact database based upon undesirable criteria. The type of data you have and the marketing channels you use to reach customers and prospects will determine the types of suppression files you’ll want to consider. A suppression file is applied by taking a dataset and comparing it against the suppression list. Remove records from the original dataset that are in both files. In this way, your dataset becomes cleaner and more accurate.

First, we’ll talk about why you need to create and maintain suppression lists. Also, I will outline types of suppression files used for data hygiene and quality. Lastly, I’ll discuss types used for marketing strategy.

Why should I create and maintain suppression files?

  • Deliverability rates will improve. Not only with email, but also postal mail. It goes without saying, but your business won’t grow if you aren’t reaching your intended target.
  • Email click-through rates will increase. Without being overshadowed by the contacts you’d rather have suppressed, your actual clicks will carry more weight.
  • You’ll remain CAN-SPAM compliant. The CAN-SPAM Act of 2003 requires that emailers have an “unsubscribe” option on all emails. Also, customer opt-outs must be honored within ten days and maintained on an updated suppression file. Non-compliance can result in penalties of up to $41,484.
  • It’s easier to send targeted offers. For acquisition marketing and brand awareness, you’re wasting money to market to existing customers. You wouldn’t send an existing customer a trial offer or a new account discount. Suppression files can help you better target offers in your customer’s buyer journey.
  • Your confidence in your data will increase. Maintaining and updating suppression files will keep your data quality top-notch. It’ll also give you confidence that at any moment, you could pull your data for marketing purposes and have, at your fingertips, the most accurate and clean file possible.
  • Suppression files reduce waste and provide cost-savings. After applying your desired suppression files, you’ll reduce the cost of messages never reaching the intended recipient or recipients who aren’t likely to respond to your offer.
  • Improves your ability to create relationships with customers and prospects. Maintaining an accurate database ensures that you’re communicating with the correct individual in the manner they desire.

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What types of suppression files should I use?

There are many types of suppression files. Let’s look at a few – what they are, when and how you should use them.

Hygiene and Data Quality Suppression Files

  1. Unsubscribes – These are people that have specifically asked you not to contact them via email or postal mail. Compile this list through an opt-out link or telephone number. This list should be kept current and suppressed for each mailing or email broadcast. Failure to comply with email unsubscribes can lead to noncompliance with the CAN-SPAM ACT of 2003.
  2. National Do Not Call (DNC) Registry – Created in 2003 by the Federal Trade Commission; the National DNC registry is a list of individuals who have indicated they do not wish to receive solicitations via telephone. While some organizations are exempt from compliance, most marketers will need to scrub their phone numbers before making calls.
  3. Bounces – This is important for email sends. Keep a list of all the bounced emails to run against before your next send.
  4. Profanity – It happens. Individuals not wanting to give out their correct information create fake email addresses and postal addresses using foul-mouthed vocabulary. Create a database of words and simple phrases that would make a sailor blush and then use this database to cleanse your marketing databases.
  5. Bad Addresses – Bad addresses exist in postal and email data. Sometimes the information is incomplete or misspelled. FYI – Many in the industry refer to undeliverable mail as a “nixie.”
  6. Duplicates – Though not a separate file you need to maintain and update, eliminating duplicate names and addresses in your file is another suppression tactic. Duplicate removal ensures that an individual is only listed once in your marketing file.

Hygiene and Data Quality Suppression Files Requiring A Service Provider

  1. National Change of Address (NCOA) – A service maintained by the U.S. Postal Service. When individuals or businesses move, they can register their new address with the postal service and their mail is forwarded to them for a set amount of time. Once that time has expired, the record becomes undeliverable. Although an authorized service provider must complete this service, you will receive back the address updates and nixies (undeliverable records). Update any changed addresses in your customer database. Use the nixies to create a suppression file for future campaigns.
  2. Prison suppress – To avoid mailing to federal and state prisons and correctional facilities, you can suppress these addresses. A qualified and licensed service provider will perform this service for you.
  3. DMAChoice – The Data & Marketing Association (DMA) began the Mailing Preference Service (MPS) in 1971. Through this service, individuals could opt-out of receiving advertising mail. DMAChoice is an expansion of the MPS and compiles a database of individuals who would prefer to not receive advertising through the marketing channels they specify. The DMA requires members to use this service for suppression and encourages other organizations to do so.
  4. Deceased Suppress – It can be a tricky and sometimes sensitive situation sending mail to someone who has passed away. If you choose, your list is run against the Death Master File (DMF), compiled by the Social Security Administration. Please note that this service doesn’t guarantee 100% removal of deceased persons. This service has to be performed by a service provider, such as ANS.

Strategy-Based Suppression Files

  1. House-File – This suppression file is your customer file. Omit these folks from all prospecting campaigns through social media, email and postal mail.
  2. APO/FPO – These are addresses to overseas military personnel. Regardless of their interest in your product or service, suppression may be necessary due to geography and the logistics of their situation.
  3. Non-Buyers (Evangelists) – These are the people who have been on your file forever, but they just aren’t going to buy. While they are helpful in promoting and supporting your brand, they usually don’t warrant receiving all of your offers. It is best only to send them information about new products and services.
  4. Non-Responders – These are the people who have never opened or clicked on your email or contacted your business after their initial interaction. Once upon a time, something interested them in your company, but if they haven’t re-engaged with you in the past six to twelve months, it’s time to move on.
  5. Unqualified Leads – These are contacts that need further nurturing before they buy. Segmenting these individuals into a separate suppression file will make it easier to target only those who are ready to purchase.
  6. Geography – Perhaps you have specific geographic areas you can’t provide with your product or service. By keeping a suppression file of those countries, states, cities, zip codes, etc. you can quickly remove matching records from an email or postal campaign to remain in the locations you desire.

Finally, the goal of marketing is to get the right deal to the right people at the right time. All marketing efforts cost businesses money. Suppression files are a sure-fire way to make sure you don’t waste your time and money with dirty and unqualified data.


P.S. At ANS, we specialize in clean data and suppression files.  Therefore, as a service provider for the services I’ve detailed above, we will ensure that your marketing data is clean. Call Patricia Thompson today for your FREE database consultation at 1-800-434-1851.


For more information about the data services we offer at ANS, please click here.

For more posts written by Wendy Harwood, click here.

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