As a way to boost to open rates and increase engagement, you can test and try out different subject lines for emails that are sent to a random portion of your subscribers with the top performer being sent automatically to the rest of your recipient list.
How do I get started?
1. Once your draft is ready to publish, click on "Continue" and on the "Publish" page, scroll down to "Run a title test".
In this section, you'll be able to enter some alternate titles, choose the size of your test, and how long you'd like the test to run for.
Tip: The recommended test size is 50% of your recipients for a test duration of one hour. This means that once your post is published, 50% of recipients will receive an email with one of the experimental titles. After one hour has passed, the title with the highest open rate will win and be automatically sent to the remaining 50% of recipients.
2. After entering the test details, make sure that the box next to "Send via email and the Substack app" is checked. Then click "Start experiment now".
3. To see how your test is doing, click on the post on your Posts tab and click on "Test". Throughout the test duration, the open rate for each of the experimental titles will go up.
If you prefer to manually stop the test, click on "End test early" and select which email title you'd like to send immediately to the remainder of your post recipients.
What happens when the test ends?
If you prefer to let the test run for the selected duration, you'll receive an email notification that the title testing has finished with a high level view of open rates for each title, the timing of the test, and which title variant was the winner and automatically sent to the rest of your subscribers.
All this information can also be viewed on the posts stats page on the web version of your Substack.
After the test ends, Substack automatically selects the best-performing title and sends the post with that title to the rest of your audience. Your post’s title (and subtitle, if part of the test) will update to reflect the winning version.