Onboarded 500 alpha testers within 12 weeks without a marketing budget. Collected 800 email subscribers with one piece of content marketing. Was able to get more than 50% of testers using just social media.
When you're starting out, it is absolutely crucial to get first subscribers/users as fast as possible. I was able to obtain more than 500 subscribers for a small Slovenian startup without spending any money. I was using a certain framework and a lot of tests.