Tracking & UTM codes in Letterhead

In this article we define Letterhead specific tracking codes to report on links clicked.

When you add a URL to your newsletter, regardless of the block used, we "wrap" it with additional information for tracking purposes.  Please review this example depicting how Letterhead attaches tracking codes for email tracking and metrics reporting.

Original Link: 

https://www.nytimes.com/2023/09/08/nyregion/donald-trump-civil-trial-date.html

becomes:

https://link.whereby.us/muysif0rhq/?lh_aid=3584680&lh_cid=h10t1yw8qa

When a subscriber follows the updated link above, it takes them to: https://www.nytimes.com/2023/09/08/nyregion/donald-trump-civil-trial-date.html?lh_aid=3584680&lh_cid=h10t1yw8qa&di=019e0b2d1b84ebc5ce0b6d2e8278d55e

Below we explain our tracking codes:

• • lh_aid is the user hash. It's unique per subscriber.
  • lh_cid is a campaign id.
  • di is a unique hash based on ip address and time of day.
  • lh_em (not in my example) will be the subscriber's email address if it's a link back to their website.

We don't use utm because we see that as a reserved word that users may want to use themselves. For example, if we used utm_source, instead of lh_cid, then a user wouldn't be able to set their own utm_source.