Some apps have a high enough LTV - the total amount they earn on average per user - that they can justify paid ads, influencer partnerships, or blitzing CPC channels. But if you're building something free (or freemium) where the monetization strategy only works at scale (like most consumer apps) those channels just aren't viable early on. Your CAC needs to basically be $0.

So what do you do?

You work your butt off.

I call this method hustling up users, and here’s how it works:

- Go to where your users hang out (Reddit, Discords, Twitter, forums, wherever). - Search for people actively expressing the problem you solve - take the time to find people literally expressing the exact need you service. You’re looking to provide genuine value here, not spam people, so this step is super important. - Reach out directly - something short, personalized, and most of all non-salesy that expresses your understanding of their problem. - Ask them to try your solution and give feedback, fully acknowledging that it’s an early-stage product.

No automation, no SEO, no slop-shopping across X and Reddit. Just honest 1:1 outreach, over and over. Talking to users, etc.

I've been doing this for the past month for Memberry.ai - https://memberry.ai - my new app that is basically just a little RAG in your pocket, but I call it a "memory assistant." You can tell your memory assistant things to remember - like “my WiFi password is tulip99” or “Sarah’s kid is allergic to peanuts” - and later, you can ask it stuff. It’s a super simple app, targeted at the problem of forgetting things. I think everyone in the world can and should use it, so I want to keep the core functionality of the app (everything released so far) completely free. Which means I can’t afford to pay high CAC for user acquisition.

That’s why my first 200-ish users came from me hunting down people complaining about forgetfulness, messy notes, or overwhelmed brains… and DMing them, one by one. Which means now I have a user base.

The best part? These users are now invested. They give detailed feedback, request features, and actually feel like part of the journey - because they are. And in the early early stages, it also helps you validate your idea and ensure you’re solving a real problem people actually have.

This method won’t scale forever. But it will get you from 0 → early traction - with no money and no audience, just raw hustle. If you can make something cool enough that people want to tell their friends about it, then this method can build you a unicorn without you spending a dime on paid channels.

I will also add that, to date, this is really the only method I know of besides sudden viral success on social media, which is possible in some cases but it doesn’t work for every type of product. I actually don’t remember who I learned this from (some business mentor of mine I’m sure, and probably several people over the years) but many well-respected startup bros have recommended it, including Sam Altman in the YC Startup School videos, if I remember correctly.

If you're building something like that, this playbook works. Happy to share templates, tips, or war stories in the comments - just let me know what you want to know!