I started out by contacting my network so I had a base of ~400 subs for my first edition.
After some quick searches on Substack I was surprised to see that the volume of subscribers for some keywords like #bootstrap #indie was quite small.
So that gave me the confidence to go ahead.
Once I launched I shared it on Twitter and Hacker News. That helped pick up some additional subscribers.
I'm now #1 on Substack for those keywords which is insane. After 1 issue ¯\(ツ)/¯
All in all, I'm really happy with the way it's gone. I curate this content for fun anyway. Now I have a growing audience who will hopefully benefit from it too!