In this lesson, you'll learn how to merge (or combine, as Mailchimp calls it) two audiences (lists) into one. We'll cover two methods for doing this, and will discuss what happens when you merge two audiences.

What's an Audience?

In Mailchimp terms, an Audience is what other email platforms call a list. It is a container for your contacts and the information you know about them. An Audience is like an address book, but it also contains other information, including the campaign you have send to the members of your audience and metrics relating to your contacts' engagement with your campaigns.

Mailchimp allows you to have multiple Audiences in one account, although they recommend that you have only one. Until May 2019, anyone with a Mailchimp account could create multiple audiences. After May 2019, Mailchimp changed its plans and the features of those plans. Now, someone on a Free plan can only have one audience. If you were on a free plan prior to May 2019 and had created multiple audiences, you are able to keep those audiences but cannot create any more. If you delete one, you can't create a new one to replace it.

Why do people create multiple audiences?

The reason a lot of people created multiple audiences in the past was for segmentation reasons. They assumed that the best practice was to have an audience for each "segment" they wanted to create.

There are several reasons that Mailchimp recommends that you only have one audience, even if you have, or can have, more than one:

1. Each Audience represents a separate database of contacts. Having two audiences is like having two separate address books. People can be in more than one audience. Updating the record for someone in one audience does not automatically update the record for that person in the other audience.
2. Someone in more than one audience is counted twice towards your Mailchimp plan. It can become expensive to maintain multiple audiences when you have a lot of crossover between them.
3. Adding a custom field to one audience does not also add it to the other audience. You can manually add the same field to more than one audience, but each custom field is specific to the Audience where you created them.
4. You can't create a segment that combines contacts from more than one audience. This is because segments are specific and limited to one Audience. This means that you can't send an email to someone in one audience based on them having opened a certain email in a different audience.
5. You can't send an email campaign to people in more than one audience. To do this, you'd have to create the same email campaign multiple times, once for each audience.

There are some scenarios where having multiple audiences might make sense (e.g. your two audiences are completely separate and have little or no crossover of members) but in general it is best to follow Mailchimp's advice and maintain only one audience.

Why merge Audiences?

If you find yourself managing a Mailchimp account with multiple audiences, it probably makes sense to combine, or merge these audiences into one. However, this is not necessarily a simple process. You have to be careful how you combine your audiences to avoid losing valuable data when you do. However, there is some data that will be lost however careful you are, because some data cannot be included when you merge two audiences.

Options for Combining Mailchimp Audiences

There are two basic ways to combine a Mailchimp audience.

1. Mailchimp provides a tool for combining audiences. This is quick and easy, but is likely to result in the loss of data about your contacts that you may want keep.
2. Export your contacts from both/all audiences, combine them into one spreadsheet and then import the combined data back into your master list. You'll still lose data, but will have say over the data that is kept.

I almost always recommend option 2. It takes more work but gives you more control and greater flexibility over the process and the results.

Data you will lose when you combine audiences.

When you combine audiences, you will lose the following information about the audience you are merging:

• Group and tag data
• Data in custom fields unless those custom fields also exist in the other audience
• Information about email engagement, e.g. opens and clicks
• Member rating
• Opt-in time stamps and signup source information
• Permissions those contacts gave you in relation to GDPR.

Note that only Subscribers will be transferred across. Other contact types can't be transferred with this tool.

If a subscribers in the list you are merging has the same email address as a subscriber in the master list you are merging into, those subscribers will be merged into one. Otherwise a new subscriber will be created in the master list.

Email campaigns you've created cannot be merged either.

Using the Combine Audiences Tool

These are the steps for using the Combine Audiences tool. If you have multiple audiences and want to combine all of them into one list, you should merge two lists at a time.

Before you start, be aware that if you have sent an email campaign to the audience you merging into the master audience, you will have to wait until 7 days after that campaign was sent.

1. Back up both lists by exporting them to a CSV file. This can be opened in Excel and/or imported back into Mailchimp if you need to.
2. Decide which list you will keep. We'll refer to this as the master list. This is probably the list with the most contacts in it, but it could be the smaller of the two if there have been more email campaigns sent from that campaign.
3. Click the Audience button in the top-left menu of your account. You'll be taken to the page for one of your Audiences.
4. In the Audience menu on the right side of this page, click the dropdown and choose Manage Audiences.
5. Locate the audience you are merging into the master list, click the dropdown next to its name, and choose Combine Audiences. Remember - this is the audience that will be merged into your master list.
6. In the dialog that appears, choose your master audience and click Next.
7. You'll then see another dialog that warns you that you will lose data when you combine audiences, and provides a link to a page that describes what will be lost.
8. Type CONFIRM to confirm that you want to continue, then click the button to Combine Audiences.

Once this process is complete, you'll have one master audience that contains all of the subscribers from both lists. The audience you merged will still be there. You may wish to delete that audience now if you no longer need it. Otherwise, you could also consider archiving any unsubscribed contacts in that list as well as any non-subscribed contacts (those that came from an ecommerce integration). Archiving them means they no longer count towards your Mailchimp plan and you will no longer have to pay for them.

Steps using export/import

As I mentioned earlier, I prefer using this method for merging audiences because it gives me more control over what I keep and what I lose. For a start, this process does not do anything to the audience being merged. That means that if I make a mistake during the merging process, I still have the original list to refer back to.

These are the steps for using the Export/Import method of combining audiences.

1. Back up both audiences by exporting them to a CSV file.
2. Open both CSV files in separate spreadsheets (you can use Excel, Google Sheets, Numbers or any other spreadsheet software you have available).
3. Identify any custom fields that exist only in the list being merged.
   • Add new fields to the master audience in Mailchimp for each of the custom fields that you want to keep.
   • Add new columns to the master spreadsheet for those fields (i.e. add new headings for each field to the master spreadsheet).
4. Copy and paste the data from the spreadsheet being merged into the master spreadsheet.
   • When you do this, make sure the column headings line up with the right data.
   • It doesn't matter if you have some columns that are mostly empty as long as the data in each column matches the title of that column.
5. Add another a new column to the master spreadsheet and call it Merge.
   • The following steps will be easier if you insert this new column as column A, i.e. the first column in the master spreadsheet.
6. Sort the list by Email address. When identifying duplicate contacts, Mailchimp only looks at the email address.
7. With all the contacts sorted by email, any duplicate contacts will be shown one above the other.
   • Review each duplicate pair and decide which one you want to keep as the master version of that contact.
   • Put an X in the Merge column for the version of the contact you don't want to keep. Otherwise, leave this column blank
8. If you find that both versions of the duplicate contact have fields you want to keep, manually combine those values into the master version of the contact.
   • For example, the merge contact may have a last name but the master copy may not. In this case, you'd copy the last name from the merge contact into the master contact.
   • This step may take a while to complete, especially if you have a large list. It's up to you to decide whether the effort is worth it in terms of the data you want to keep.
9. Once you have finished selecting which duplicates to keep, sort the list again, this time using the Merge column as the sort field. Then, select and delete all the rows with X in the Merge column. These are the rows you don't want to import, so you need to remove them.
10. Now, save the spreadsheet as a new CSV file and import the file into Mailchimp.
    • Choose the master audience as the one you are importing into. This is the one that will be updated.
    • Make sure you choose the option to update duplicate contacts.
    • Map sure every column in the spreadsheet to a field in the master Audience that you're importing into.
    • That way, data from any new fields in the merged list will be added to the master list.
11. Once the import has been completed, you can then either delete the old audience or archive all of the contacts in it.
    • Remember that this process does not remove any contacts from the merged list, so you have to remember to do this once you're happy with that the merge process has worked as planned.