When Terrell Johnson launched on Substack, he had no intention of rolling out a paid newsletter. He was just trying to escape Mailchimp's expensive fees and liked that Substack would send his newsletter for free. About a decade earlier, Terrell had created HalfMarathons.net, a running focused website that grew so popular that at one point it was generating six figures in revenue just from Google Adsense.

His free newsletter served mostly as a form of marketing for the website, but he eventually began to wonder if his most engaged readers would be willing to pay for it. So he flipped on Substack's payment features, and while it wasn't an overnight success, he's gradually grown it into an impressive community of paid subscribers.

I interviewed Terrell about where he got the idea for HalfMarathons.net, how he built up an audience, and why he eventually grew to distrust Google as his primary traffic driver.