Increase Your Email Open Rates By 10% With This Strategy

I focused on paid subscribers and active free subscribers.

May 25, 2025

A friend has a paid subscription to The PIMM Trader.

When he got his first paid subscriber email, he called me and said, “I thought I had a paid subscription.”

I responded with, “You do. You should have gotten your first paid post email.”

He said, “I was just confused. Your post told me to subscribe. I wondered why I needed to subscribe if I was already subscribed.”

I thought about it and said, “That’s a good point. I didn’t realize it. I was making one post for everyone and included the same subscribe buttons.”

He coached me by saying, “Typically, your emails to paid subscribers should be different than the ones you send to free subscribers.”

This short conversation shifted my mindset in how I publish posts.

First Change: Tailored Posts for Paid Subscribers

I stopped including subscribe buttons and calls to action to upgrade to paid subscriptions for my paid posts.

I wrote the post with the information I wanted to share with them.

I put a refer button at the bottom of the posts so my paid readers can earn referral bonuses since any subscriber can earn them.

Second Change: Different Buttons for Free Subscribers

I stopped including the subscribe buttons in my free posts.

I would write the content and include the call to actions so they can upgrade.

I also included the referral button at the bottom of the post.

Then I would publish the post.

It takes Substack about 5 minutes to send all the emails to the subscribers.

After 5 minutes, I would edit the post and include the subscribe button near the top of the post.

This would encourage anyone visiting my site to subscribe, but not confused my free subscribers since the email would not have it.

Third Change: Focus On Active Subscribers

Here is where I saw the biggest impact to my email open rates.

I decided to focus sending post emails to paid subscribers and active free subscribers.

Paid subscribers tend to be more active and open emails more often.

Free subscribers are less likely to open emails.

People tend to value things less when they’re free.

I decided to only send emails to subscribers that have 3, 4 or 5 activity stars.

I came up with this publication strategy.

Step 1: Write a free post to paid subscribers. I would excluded all the buttons except for the referral button. Then I would publish the post as a paid post.

Step 2: After 5 minutes, I would edit the post and include the paid subscription call to action buttons. Then I would change the post type to a free post and publish it again.

Step 3: Filter subscribers for the free subscription type and 3 or more activity stars. Then I would select all of them and click the send email button.

Step 4: I would write the email letting these active free subscribers know about the free post and paste the link to the post.

Step 5: After 5 minutes, I would edit the post to include the subscribe button near the top of the email and publish it again.

Four Change: Let Free Subscribers Know About Paid Posts

I decided I would give my free subscribers have the same stock ideas at the paid subscribers.

Free subscribers would get the tickers and the paid subscribers would get my detailed analysis and the charts.

I followed the same process but I would not change the post type a free post.

I kept the post as a paid post.

The free subscribers would get an email with the tickers, a link to the paid post, and the call to action buttons to upgrade their subscription.

My Results

I was getting about 20% to 21% email open rates before this new strategy.

In less than a week, I started seeing a slight increase in my email open rates. I initially thought this was a coincidence so I decided to track it longer.