I just published issue #3 and am gaining about 25 subscribers per issue. Really loving Substack as a publishing platform so far!
Check out the latest issue where I interview microstartup king and fellow IndieMaker Hari (also known as 1hakr - https://www.indiehackers.com/1hakr)
http://alternativeassets.club/why-isnt-the-website-investing-space-bigger/