- Email address
- A shared customer/contact ID if intentionally synchronized
- Phone only as a carefully reviewed secondary field
Marketing list workflow
Merge Email Subscribers with Customers
Compare an email subscriber export with customer data to distinguish buyers from non-buyers, find customers missing from the marketing list, or add customer attributes to subscriber records.
🔒 Local processing for normal jobsEmail matching
Recommended setup
Keep Everything is useful because subscribers who are not customers and customers who are not subscribers remain visible.
A spreadsheet match does not determine marketing consent. Treat subscription permission as a separate field and source of truth.
How to compare the lists
- Add the subscriber and customer exports and select the correct data sheets.
- Choose Keep Everything and map the email columns.
- Review duplicates and unmatched records. Use a second field only when it truly represents the same person in both files.
- Select the fields needed for segmentation or reporting, then download the workbook.
People can subscribe and purchase with different email addresses. A non-match may represent a genuine identity difference rather than a formatting error.
Common list issues
The same person may use one email to subscribe and another to buy.
Role addresses and family inboxes can correspond to multiple people.
Do not infer opt-in status merely because a customer row matches a subscriber row.
🔒
Normal jobs stay on your device.
MergeStudio processes normal spreadsheet jobs locally in the browser.
Compare subscribers and customers
Keep the unmatched rows visible and export the fields you need for analysis.
Open MergeStudio →MergeStudio combines spreadsheet exports only. It does not change subscription status or consent in any email platform.