From a curiosity about AI to US$105,000 a month, in one PHP file

Pieter did not start from a problem. He started from curiosity: when Stable Diffusion came out, he installed it on his Mac and posted what it made on X. 8 It was bad at people but good at houses, so he made thishousedoesnotexist.org. 8

People got bored of the houses, but the model was good at interiors. With a new technique called image-to-image he could upload a photo of a room and restyle it. That became Interior AI. Within a week it made US$10,000 to 20,000 a month, and two years later it still made US$40,000 to 50,000. 9

To improve Interior AI he learned fine-tuning: training an existing model on one goal. For fun he trained it on photos of himself, and it learned his face. "So I was like, this is another startup." That was Avatar AI. 10

His thesis at the time, posted in December 2022: the real opportunity in AI for most people is not the AI itself but a front end around it. 11

Avatar AI launched at the end of October 2022. Ten days later it had made US$100,000 from 2,943 sales, about US$33 each. 2

Then the margin vanished. The company that ran his model training saw the revenue he posted and raised its price from US$3 to US$20 per training. He was selling at about US$30, so the profit was gone. 12

He went looking for another platform and asked Replicate's CEO to add the training method he needed. The answer was no, because it took too long on their GPUs. He kept asking, and a week later they launched it. By his account, the avatar apps that followed mostly ran on Replicate too. 6

Pieter saw the avatars as hype. Cartoon and painted styles hide the AI's mistakes on a face; a real photo does not. He decided to solve the hard version: realistic photos, without a photographer or a studio. 13

It took two months, and he admits he was procrastinating because the project felt endless. Marc Kohlbrugge pushed him to ship. Photo AI launched on 10 February 2023. 1

The first version had no real login. You paid through Stripe Checkout and received a login link. Proper Google login came a year later. His rule: decide what not to build, because there is no time. 14

By July 2023 the whole product was almost 14,000 lines of raw PHP with inline HTML, CSS and JavaScript, using jQuery and no other framework. It had 1,872 paying customers and made US$61,808 a month. 3 In March 2026 it was one file, index.php, of 40,870 lines. 4

He cannot write Python, which most AI work needs, so he hired one AI developer, who worked with him for 10 months. 5

With more than a million photos generated a month, he stopped judging settings by eye. He tested different generation settings on 10% of users and measured which photos they marked as favourites or downloaded. The winning settings became the default. 15

The training data mattered more than training time. Face crops alone lost the body's shape, so he mixed full-body photos with face crops, automatically. 16

In June 2023 he added a try-on mode: upload clothes, and your AI model wears them. He aimed it at Shopify sellers who need model photos, at US$29 a month, which he called at least 30 times cheaper than a shoot. 17

In August 2026 he added a full video editor that generates scenes with the user's trained models. 18

Pricing in October 2026 has four monthly plans: Starter US$19, Pro US$49, Max US$99 (marked most popular) and Ultra US$199. Only Pro and above allow commercial use. 7

If more than 1% of payments are disputed, Stripe, Visa and Mastercard can shut the account for good, and each dispute costs a US$30 fee, returned only if you win. For a decade he ignored disputes and lost almost all of them. 19

In 2026 he had AI help him build a responder. When a dispute arrives, the site collects what the customer did in the app and sends a detailed PDF as evidence. The first big win was a US$1,199 dispute from a customer who had generated thousands of photos. 19

1. How much does a user cost in GPU time, and how did the margin move from 2023 to 2026?
2. Which plan brings most of the revenue, and how long does a subscriber stay?
3. Where do new customers come from today: X, search, or paid creators?
4. Why a monthly subscription, when Avatar AI sold one-time packs?