From 0 to First Sale: How I built this AI tool with Next.js (and asking for help!)

Hey Indie Hackers!

I'm a solo developer, and several days ago marked a huge milestone for me: I got my first paying customer for my side project!

It's a small win ($9.9), but after weeks of coding in silence, seeing that payment notification felt unreal. I wanted to share my journey from idea to this first sale, and ask for some advice on growth.

The Problem I noticed that many users (designers, DIY enthusiasts) struggle to turn photos into clean line art/sketches. Most existing tools either:

Just desaturate the image (messy results).

Are overly complex desktop software (like Photoshop/Illustrator).

Don't support SVG export well.

I saw people on forums asking for a "one-click" solution to get clean outlines for coloring books or laser cutting. So, I decided to build it.

The Stack I kept it simple to ship fast:

Frontend: Next.js (deployed on Vercel)

Backend: Next.js

Payment: Creem

The Product: GenLineArt

The Dilemma I haven't spent money on ads. Instead, I focused on SEO (targeting long-tail keywords) and submitting to search engines.

Here is where I need your help: While I finally got my first sale, my traffic is still very low. I have users registering every day, but the conversion rate is tough. I feel a bit trapped—I've validated the idea with one sale, but I don't know how to scale from 1 customer to 100.

I'd love to hear your thoughts:

Should I focus on more content marketing/SEO?

Or should I try cold outreach to designers?

Thanks for reading, and happy building!