What is a merge tag?
In order to use Email Analytics to collect individual-level data on your subscriber behaviour, we need a way to identify your subscribers in our tracking codes. We do this through the use of a merge tag.
Depending on the type of mailing software you use, merge tags may also be known as personalization fields, substitution strings, or personalization tags. These tags allow you to insert data from your mailing list directly into your email campaigns. For example, if you are a MailChimp user and you'd like to insert your subscriber's first name into your email, you might use the merge tag *|FNAME|*. Every time MailChimp sees the tag *|FNAME|* in your email, they will replace this tag with the unique data associated with each recipient in your list.
Each ESP or mailing platform has a slightly different way of handling these tags, which is why we ask that you choose your ESP from our drop-down menu, which will use the known recipient ID merge tag we have on record for the ESP (where we are aware of one) or type it directly in the box. By correctly identifying the merge tag for your mailing platform, you're ensuring that Litmus can collect all the data you're looking for and match it back to the subscribers on your list.
To ensure Litmus does not collect or retain personally identifiable information (PII) for your subscribers, our tracking codes do not support “email address” merge tags. Instead, we use the Unique User ID (UUID) merge tags that the ESPs support. If Litmus is aware of an ESP’s UUID (or equivalent) merge tag, it will automatically be populated within the tracking code when the ESP is selected from the supported ESP list. In the example above MailChimp has been selected and their UUID merge tag of *|UNIQID|* has been automatically populated in the tracking code.
If an ESP’s UUID merge tag is unknown to us, or the option of “Other” is selected from the ESP list, you will have the ability to manually type it in directly before the tracking code is generated. This is shown in the below image:
Can a merge tag be my recipient's email address?
No. To ensure no customer PII is stored by Litmus, any data that is passed to us via merge tags that resembles an email address will be scrubbed and not show up in subsequent Email analytics reports. Instead, we lean on the ESPs UUID for each recipient to allow you to tie back data captured to a specific contact. If you'd rather use another unique identifier that your ESP supports or add additional, bespoke (PII compliant) merge tags, just find the merge tag associated with the data field and type it into the ‘custom parameter’ field in step 2 of the tracking code creation flow.
What if my ESP isn't on the list?
IIf your ESP isn't listed, or we do not automatically populate a UUID for a selected ESP, you can manually type the appropriate merge tag by selecting “Other” in the ESP dropdown, and you can enter your merge tag in the field labelled “What’s the merge tag for your provider?”.
If your ESP has a default merge tag for a recipient's ID (UUID or similar, e.g. "lead ID", "Contact ID", "Subscriber key", etc.) that isn't listed in our dropdown, let us know and we'll get it added.
What if I have a custom set-up with my ESP?
In some cases, you may have a custom integration set-up with one of the ESPs listed in our dropdown box. Make sure you check with your ESP or technical team to see if the merge tag for recipient ID changed with your custom set-up. If you have a custom tag, be sure to use that one instead.