I'm going to let you in on a dirty little secret. I hate newsletters. Hates 'em, my precious. Don't read them. Don't write them. Don't send them. I subscribe to exactly three and they are all people I know and care about. Do I open them and read them? No. I get what I need from the subject line and I move on.
Time is a commodity. It has value - possibly the only value - because it is the measure of your finite life. I begrudge no one reading a newsletter, if that's their thing, but in a world that competes for time and attention, the newsletter feels -- I don't know -- not my cup of happy juice.
This is a long way of saying I am absolutely the wrong person to talk to about how to increase newsletter subscribers. I am so bad at sending newsletters that MailChimp fired me as a customer. Seriously. I hadn't served a newsletter in so long, they deleted my database of subscribers. All 60 of them. S'okay. I know all of them. If they want to know what I'm up to, they call or text to ask.
Still. We want to reach readers. We want to let readers know how to find out what we're doing and what's coming up. For some genres, I feel like newsletters are totally appropriate. For scifi, I wonder. I'm actually thinking that I might be better served to leverage a Tik Tok format for a pseudo newsletter-y type of thing. Or Discord. Or some other place where my fellow geeks hang out. This could all be rationalization for the fact that I'm bad at newsletters.
Suppose, though, that I *did* start some 'contact readers' push. How would I draw people to consume my content? Cross pollenization. It has to be done carefully, but you can leverage one platform's content on other social media platforms. Link them all back to a single landing page with you pertinent info - new release, find me at this place at this time! Whatever you want readers to know. The key to success is the same as it in newsletters - offer value. Something silly. Something charming. Something that makes readers feel. Control that and ask for responses. Engagement equals reach. Reach means more eyes. Does it work? Don't know yet. It would have to be tried and tested. The level of effort has to be weighed against the return.
And that's on each author.