Your first 100 Subscribers?

It's not about a SaaS but a publication (well, there's a monthly subscription so it's quite similar in a sense). I had no audience, like maybe 100-ish followers on Twitter which were mostly friends and inactive users. A month ago, I decided to launch a publication on Marketing, my core skill. But I knew there were thousands of newsletters about Marketing. So I decided to promote a “bootstrapped” angle — how to get more people in front of your project without spending big money, run ads, take sales calls or play hacks. To launch, I built a landing page that was as simple as it could be. It only included a manifesto, promoting 21 principles on marketing, and a teaser on the upcoming publication I was launching. I went to Reddit and offered free Marketing help to entrepreneurs, if they posted the URL to their website and asked me a specific question. I added my manifesto URL in the post so people could check it out beforehand and see if this would help them. Hundreds of people commented. 120+ subscribed to my newsletter in the next 2 days. A month later, over 1K people are reading my work every single day.