If you've ever received an email like this, it's because newsletter platforms like Substack track engagement metrics—including whether or not you open their emails.

I can’t count how many times I’ve received an email like this, and this post is going to dive into the mechanics of emails and what these metrics are really tracking.

What is being tracked

Let’s start with the Subscriber page in your Substack Dashboard.

The subscribers page is your newsletter contact list. Here is everyone that subscribes to your newsletter. If anyone has given you their email address, they end up here.

Substack tracks various metrics on these email addresses. The primary metrics (and the default ones shown) are:

• Free vs Paid Subscriber - Self explanatory, but this shows you if the email address is a free subscriber or a paid member of your newsletter.

• Activity - This is a 5 star rating system developed by Substack to share “a high-level rating of how actively the subscriber has used your newsletter in the last month, including email opens and web views.”

• Subscription Date - This is date the email address was first added to your newsletter subscription. The first time it entered your contact list.

• Emails Opened - This tracks how many emails were opened in the inbox of this email address.

• Links Clicked - How many times this email address clicked a link when they opened your newsletter in their inbox.

• Subscription Source - What brought this email address to your newsletter.

If you click the Columns button on the subscriber page, you will see many other data points being track that let you really refine and drill down your audience. But I’m going to focus on these primary ones.

How it works

So how is Substack actually collecting this information? How does it know when someone has opened an email or click a link?

For email opens and reading in an inbox, Substack is using a tracking pixel in images.

A tracking pixel is a tiny, invisible image (usually 1x1 pixel) embedded in the email. When the recipient opens the email, the image is loaded from Substacks server, allowing them to track that the email was opened.

Substack uses tracking pixels in its newsletters to measure open rates. When a subscriber opens a Substack email, the pixel loads, and Substack records the open.

For link clicks, Substack is using a tracking system that creates unique URLs for each email address the newsletter is sent to.

When a subscriber clicks a link in an email, they are briefly sent through a Substack URL that records the click before forwarding them to the intended webpage. Either your newsletter or an outside link.

This allows Substack to track which links are being clicked, how often, and by whom.

Substack used both of these methods to understand who is reading your newsletter and where they are going once they’ve read it. This data is shared in your Subscriber page and used to create the Activity 5-Star metric.

Limitations to know

Tracking pixels and link click tracking in email newsletters come with significant limitations, due to privacy settings and different email clients. Most modern email clients, now preload or block tracking pixels to protect user privacy. This means an email may appear as "opened" even if the recipient never actually viewed it, or it may not register at all if the recipient's email client blocks the pixel. As a result, open rates can become an unreliable metric.

Similarly, link click tracking is affected by browser privacy settings, VPNs, and ad blockers, which can strip tracking parameters or prevent redirections. Some users may also copy and paste links directly into their browser instead of clicking them, bypassing Substack’s tracking entirely.

Which get me to my opening line, “It looks like you haven't opened our email in a long time.” I use an email service that blocks tracking entirely, and I’m not alone in this. If I’m subscribed to a newsletter, I show up as a 1 or 0 star rating in Substack’s Activity. I’m shows as 0 star subscriber to my own newsletter.

I open most newsletters I’m subscribed to, but my email client prevents that data from ever getting back to the sender. So your subscriber list may show low open rates, but that might not be the whole story. Particularly you cater to a more tech savvy or privacy focused audience.

There is an additional feature now showing up in email clients that allow the use of one time or temporary email addresses. These are the subscribers you have that have an email address of random numbers and letters. This is a further privacy measure by some users to protect themselves from tracking.

I have seen several guides o newsletters talking about purging their subscriber lists. Deleting emails that are not showing any engagement. The way this engagement is tracked in not always reliable, as explained above.

What to focus on

So what metrics can I rely on for my newsletter? I’m not saying to throw out the metrics provided on your subscriber page, but take them with a grain of salt. There are many ways they can be distorted.

Focus on actual subscriber growth, how many people are subscribing to your newsletter.

If you have a paid their of your newsletter, focus on the conversation of free to paid subscribers.

These are much more stick stats that can’t be skewed by privacy settings. Open rates are a useful reference, but they shouldn't dictate your entire strategy. Quality content and direct reader engagement matter far more than a number in your dashboard.

Additional Resources

Substack has some great articles in their support section that goes into more detail of how to use your dashboard and the metrics provides.

• Stats and Traffic

• A Guide to Substack Metrics

• How Are Opens Captured

• Subscriber Dashboard Guide

I highly recommend reading through these articles to understand how to use the Substack platform you are publishing on.

Substack’s analytics can be helpful, but they have limitations. If you're a writer, use these tools wisely. Understand what they can and can’t tell you. And if you're a subscriber, know that your email activity might not be as private as you think.

Have you looked at your Substack metrics? How much do you rely on them? Let’s discuss in the comments!

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Substack is a pretty amazing reading platform. Yes, it was originally made for writing and publishing (and is amazing at that), but has been steadily building the reading and content consumption side of the platform.

It makes sense. With so much great writing happening on the platform, you should provide a great way to consume the content.

Here is the problem I have. Much of the content is long form. Consuming long form content when you’re not ready to sit and consume, is very difficult. I need to be able to save the content and consume on my time.

This is where the Kindle comes on. It’s a device and format, I’m already in the habit (conditioned?) to work and think with long form content. Sending Substack articles I want to read to my Kindle lets me batch read them together, highlight them, add notes, and keep them offline. All for free.

A few notes and assumptions before we start.

• I don’t like reading in my email inbox. Newsletters are great, but it’s not my preferred way to read. If I have the option to keep something out of my inbox, I will keep it out.

• I’m going to assume you already have a Substack account and use the inbox/notes side of things. If you don’t, this tutorial will still work for you. Just skip the opening the article in Safari steps.

• You need to have the Kindle App already installed on your device and you need to be logged into your Amazon account in the app. I have all the articles end up on my actual Kindle device, but you can just an easily read them in the Kindle App on any supported device.

• I am using an iPad for this tutorial. All of the screenshots are from an iPad Pro running iPadOS 17.0.3. I can confirm this method will work on iOS and Chromebooks. I know Send-To-Kindle features exist on Mac, Windows, and Linux, but I have not tested them.

Let’s Begin…

The first thing we need is an article. For me this starts at the Inbox section of Substack. For you, this could be in the Substack App or your email inbox.

You’re going to find your article and open it in Safari.

For this tutorial, I’m going to use a recent article published on Technology Should Be Simple.

Opening the article in Safari will bring you to the article on the actual Substack publication page. Being on the publication URL is important for exporting the correct article.

In this example the correct URL is…

• https://technologyshouldbesimple.com/p/digital-natives

Not the internal Substack URL…

• https://substack.com/inbox/post/138237281

Next, we are going to click the Share button on the Safari Browser Bar. It looks like a square with an arrow pointing up.

This will bring up our sharing menu options. We are going to select Kindle.

Note: If you don’t see Kindle as an option, scroll all the way to the right of the app icons and click the three dots for more app options. The menu defaults to the 10 most used sharing options.

Next, the Send to Kindle menu will show on the screen. The Title and Author Name will pre-populate from the URL, but you may want to edit these. the Author name defaults to the publications URL. I always change it to the actual author name.

Next, click Send. You will receive a confirmation that your file has been sent to Amazon.

You may need to wait a few minutes, depending on how fast your internet connection is and how long the article was (pictures and graphics add a lot). In my experience, the articles are ready after 3-5 minutes.

Head over to the Kindle App on your preferred reading device (or maybe your Kindle E-Reader). If you don’t see your article in the library, filter to the Docs sections of your library. Here you will see every article you’ve sent to Kindle.

Click the article you just sent to download it for offline access.

Now you are able to read the Substack article on your Kindle App or device. You will have all the same features you have on a Kindle Book (highlights, bookmarks, notes, etc). It will even work offline.

Since the articles are now on your Kindle, you can also organize them into collections (maybe by publication). This provides a nice archive of some of your favorite articles and publications, in the event you ever lose access.

A few issues and limitations of this method.

• You are sending a one-time snapshot of the article to your Kindle. The article on your Kindle will not update if the author updates the original article on their publication. For example, spelling or grammar issues (that always seem way more obvious after you publish something).

• Formatting on Kindle is good, not perfect. You will see minor issues show up. In the example above, line dividers are used on Substack to separate content sections. These line dividers do not show up in the Kindle version.

• The article is on Kindle now, not Substack. You no longer have the social media aspects of sharing and linking to the article. You will need to log back into Substack to do any of that.

• This method will work for paid subscriptions as well if you are a paid subscribers. This is not a method for getting around a publication’s paywall.

A feature I would really like to see in the future is a way to build an automation into Substack. For example, every time I bookmark an article on Substack it automatically sends the article to Kindle. This isn’t possible at the moment, due to limitations/restrictions in Substack. But it would be very helpful to have in the future.

If you found this tutorial helpful or have anything to add/questions, please let me know in the comments.

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