Is it beneficial to give trial access to the paid newsletter?

Trials are only useful if they help users realize that they need the product (in this case, the newsletter/articles) and lead them to subscribe. So it really depends on the content—if the articles are disconnected and don’t follow a coherent editorial line, users might just read what interests them and leave, as happened to you. That said, I don’t think that’s the case for you, as you seem very structured in your communication. I believe that those who used the trial, read the content, and then canceled were simply people who were unlikely to pay for access to that specific content anyway. A trial is always a double-edged sword, but it should be tested over a long period to see if it actually leads to an increase in subscriptions. And it should be analyzed as a whole, not just on a case-by-case basis. For example, if your newsletter grows by 10% per month for three months without a trial, but grows by 12% per month with a trial, you might still see many cancellations. However, in the end, you’ve gained a 2% increase in subscribers thanks to the trial. You could also run surveys among those who signed up and canceled, or among your entire community. Data makes every case different. Personally, I think trials are always a good option, especially if you believe your content is valuable.