The newsletter format works best for long texts. They don’t get lost in your feed, unlike social media where they always show up at the wrong time. Newsletters lie quietly in your mailbox, waiting to be read. I think there’s a sort of renaissance of these subscriptions now—everyone's tired of messengers and their unpredictable algorithms, where only 20% of subscribers actually see what you write. Sure, there’s RSS, but it’s barely alive—it's geek technology now. Newsletters are much more personal and inviting. They get to your inbox and stay there.
I have around 670 subscribers (I don’t attract new ones, the list grows slowly on its own). Only half of these users actually pay for the newsletter—others are subscribed for free due to friendship and other reasons. Lots of people have dropped off because of problems with their payment cards (they expire, get lost, the money sometimes runs out). The average open rate is 70%, and after each mailing 3−4 people unsubscribe.