I mostly focus on my MRR or paid subscribers when evaluating my Substack newsletter's success, but I was pleasantly surprised to see I had crossed 5,000 free sign ups (total email list) for Blogging Guide.
I started this newsletter in February, and it has been far more successful than I would have guessed.
Reaching 5,000 sign ups shows how effective Substack newsletters can be for generating leads. It also is a lot cheaper than having those same 5,000 users on Mailchimp on some other paid email marketing service.
I have yet to really market/send newsletters just to me free sign ups encouraging them to become paid subscribers, so I will be interested to see how many additional paid subscribers I can get by reaching out to this fairly engaged audience.