From 0 to €55 MRR: Building a Signal transcription bot (and learning marketing as a dev)

I started building SignalWhisperBot about a year ago because I was drowning in voice messages. Colleagues sending 5-minute voice notes, group chats full of audio I couldn't listen to during meetings. I thought "there has to be a better way."

So I built a bot that transcribes voice messages directly in Signal. No new app, no complicated setup. Just forward your voice message to the bot and get text back.

The first few months were brutal. I got my first paying user in January, but then it stayed at 2-3 users for months. Sometimes dropped back to 1. I'm a dev, not a marketer, so I had no idea what I was doing wrong.

Honestly, I got pretty demotivated and basically stopped working on it. I just let it run on autopilot while I focused on other things. The bot was stable, users could still use it, but I wasn't actively trying to grow it anymore.

Then in May, something changed. Suddenly I started getting consistent signups. My theory: AI tools like ChatGPT started indexing and recommending my bot when people asked about Signal transcription. I went from 1-2 users to 15 paying customers as of today.

That growth spike pulled me back in. I realized maybe I had something worth fighting for after all.

But the real breakthrough came when I started learning marketing. I added a quota warning system - when users are close to their limit, the bot tells them directly in Signal. No fancy email campaigns, just "hey, you're almost out of free transcription time." That simple in-app message converts better than anything I've tried.

I'm also finally setting up proper email automation and iterating on processes to lose as few users as possible - fixing signup issues, improving onboarding, that kind of stuff. Took me a year to realize I needed to actually communicate with my users outside the bot.

The game-changer was asking for feedback. I started reaching out to users to understand how they actually use the bot. One business user told me she needed file exports and speaker identification for meetings. I built those features as "Pro" tier and she became my highest-paying customer.

(Side note: Getting user feedback is still incredibly hard. Most people don't respond. Fellow builders - how do you get users to actually tell you what they think?)

Today I'm at €55 MRR with 15 paid users. Goal is €500 MRR by end of year.

The biggest lesson: As a dev, I thought building the product was the hard part. Turns out, learning how to market it and actually talk to users is just as important. Still figuring it out, but each small win teaches me something new.

Happy to answer questions about Signal bots, transcription, or learning marketing as a technical founder.