I've published 7 editions now and each time I have tinkered with little things here and there. The process of researching and writing about an interesting topic is a reward in itself, so that placates me even if I wanted to acquire more subscribers by now :). More than that, some people have sent me really nice messages that keep me going. I would love to learn more best practice tips on how to maximise readership and open rate, and I look forward to learning that on Indie Hackers!