What is substack.com in my analytics, and which newsletter was it?

Why visits show it

A Substack post lives on the web as well as in the inbox. When someone reads it in a browser and clicks your link, the browser passes on the origin of the page they were on: substack.com for the Substack site, or the publication’s own address, such as name.substack.com. A publication that has connected a custom domain shows that domain instead, and you may not recognise it as Substack at all.

What it hides

Browsers by default send only the origin to another site, never the path. So name.substack.com tells you the publication, not which post. And substack.com alone tells you even less.

The larger gap is the email. Many readers of a newsletter read it as an email, and a click from a mail app arrives with that app as referrer or with nothing, which counts as direct. So the substack.com row is the web part of a newsletter’s clicks, not the whole of it. Substack’s own post stats count link clicks per link, which gives the author a total to compare with.

How newsletter platforms tag links

Some platforms add UTM tags to every link in a post on their own. beehiiv’s help page says it does this by default: utm_source is the publication’s domain, utm_medium is “Email” when the post is read as an email and “Referral” when read online, and utm_campaign is a version of the post’s title. It also says it leaves a link alone when you have already set those tags yourself, and that the publisher can switch the feature off.

So an untagged link in a beehiiv newsletter arrives with beehiiv’s tags in place of a referrer, and your analytics names the publication’s domain as the source. Substack’s metrics guide doesn’t mention UTM tags, so don’t count on them there.

How to see which newsletter it was

Hand the writer or sponsor a tagged link, so the tags are yours and not the platform’s:

https://example.com/?utm_source=makers-weekly&utm_medium=newsletter&utm_campaign=sept-sponsor

One utm_source per newsletter, one utm_campaign per issue. That credits the email and the web clicks to the same place.

With Nordva Launch

Launch counts substack.com and its subdomains as social when there are no tags; a publication on its own domain counts as a referral. A UTM tag that names a channel (a medium such as email or social, or a known source) wins over the referrer: utm_medium=email or utm_medium=newsletter (beehiiv’s default “Email” included) files the visit under email. Grouping paying customers by utm_source or utm_campaign needs Builder.