Solopreneur case studies — 9/10
Solopreneur and side-business cases
193–216 of 239
Avatar AI Made $150K in a Week — So Why Did Levels Shut It Down Himself? A Record of Walking Away from a Winning Hand
Pieter Levels's Avatar AI rode the early AI-avatar boom to roughly $150K in one week — the fastest money he had ever made. Yet instead of chasing the boom, he called it "too cheap — I want to solve real problems" and pivoted to the utility-focused PhotoAI. A rare record of quitting in the middle of success.
A Side-Business Smartphone Lens Filter Brand Sold in Two Months After Listing, Prompted by a Job Change. The Conditions for a "Perfect-Score Sale"
THE emo, a smartphone camera lens filter brand Renpei Taniguchi launched as a side business in 2020, grew by winning fans through crowdfunding and social media. Facing a job-change deadline, he listed on multiple platforms, met with 4 companies, and transferred the business to Mediair Inc. in under two months. His own verdict: "a perfect score."
Podseeker: 10 Inquiries in Week One, Then Six Months of Silence — How a Price Cut Closed a Six-Figure Sale
The podcast contact database "Podseeker" reached $1,000 MRR within months at $50/month. Right after listing on Acquire.com, it drew 10 inquiries in a week, then stalled for 6 months at a high asking price, before closing at a six-figure dollar sum after a price cut.
Four Years of Stock Photography, ¥185,000 Total. A Real Record of the "¥4,000 a Month" Median
A four-year account of selling stock photos (Adobe Stock, Photo AC, PIXTA). Cumulative sales came to roughly ¥185,000 — about ¥4,000 a month on average. Even left nearly untouched, the money keeps trickling in at the level of "one night out per month." Data that sits at the opposite pole of glamorous success stories, close to the median for entrants.
Even Air HR, a Small HR Tool with $40K in Annual Revenue, Found a Buyer — the Market Where the "Smallest SaaS" Still Sells
Air HR, a small HR software business with $40K (about ¥6M) in annual revenue, was sold to payroll SaaS company KarbonPay. Even a SaaS at roughly ¥500,000 in monthly revenue can attract a strategic buyer — a case showing that the "too small to sell" line sits far lower than people imagine.
Carrd: $2M ARR With Zero Marketing Spend and an Anonymous Solo Developer — the “Don’t Add Features” Strategy
Carrd, the one-page-only site builder, is run single-handedly by an anonymous developer known as AJ, reaching $1M ARR five years after launch and later $2M ARR, with 3.3 million sites and 2.2 million users. Marketing spend was zero — growth came from the audience built with his previous project, the free template site html5up.
Side-Business Blog "Tsuzuki Blog": From ¥42,000 to ¥1 Million a Month in One Year. Breaking Down the Published Monthly Data
Tsuzuki Blog began in earnest in January 2019 while its author handled SEO at an IT company. Month six: ¥69,000 in revenue (¥17,000 AdSense + ¥52,000 affiliate) on about 21,000 pageviews. Revenue concentrated in 2–3 VOD articles, reaching ¥1 million a month roughly one year in. We break down the published monthly data.
Peing: Built in 6 Hours, 200M Monthly PV in One Month — Sold at the Breaking Point of Virality
Peing, an anonymous Q&A service built in 6 hours by 26-year-old indie developer Seseri, hit 400,000 daily PV on day 5 and a 200M monthly PV pace within a month. Overwhelmed by server load and the limits of solo operation, it was sold to Jiraffe just one month after launch (price undisclosed).
Shift: From $80 in Week One to $50,000 MRR in 10 Years — a Laravel Auto-Upgrade Tool Run on $100/Month
Shift, which automates Laravel version upgrades, launched in 2015 with just $80 in its first week. Ten years later, it has processed over 175,000 runs and reached $50,000 MRR — zero employees, monthly operating cost of about $100. The turning point was customers telling him he was charging too little.
¥4.61 Million a Year, Five Years After Starting to Learn Programming. The Full Three-Year P&L and Playbook of an Indie Education App
An education web/smartphone app that began as a homemade tool to ease cram-school work grew from ¥120,000 (FY2023) to ¥1.47 million (FY2024) to ¥4.61 million in revenue (¥3.91 million profit) in FY2025. The developer discloses what drove each year's growth. Fully independent as of March 2025.
PhotoAI at $132K a Month, Zero Employees, 37,000 Commits a Year: Dissecting Pieter Levels' "Solo-Run" Playbook
AI photo generator PhotoAI earns $132K a month (about ¥19.8M), and Pieter Levels' entire portfolio tops $228K a month—run with zero employees. 37,000 commits a year, two-second deploys, GPT-4-automated moderation. Levels openly admits only 4 of his 70 projects hit. Here's what's actually behind his operation.
TypingMind: Quit at $600 MRR, Then $45K/Month — Every Decision in Tony Dinh’s Build-Sell-Release Loop
Vietnamese indie developer Tony Dinh quit his job at $600 MRR. TypingMind, shipped right after the ChatGPT API opened, made $1,000 on day one, $10,000 in 10 days, and later $45K/month. Meanwhile, when the Twitter API crisis hit Black Magic, he decided within two weeks to sell it for $128K. Every offensive and defensive call is public.
Month One Paid ¥400 an Hour: Four Months of Fully Disclosed Kitchen Car Sales — and the Fifth Month, When COVID Stopped Everything
Real month-by-month data from a kitchen car's first 4 months. Month one: 8 days of vending, ¥64,000 in sales and ¥28,000 in profit (about ¥400/hour by the owner's reckoning). By month four: ¥384,000 in sales, ¥334,000 in profit. Best single day: ¥50,000. Then, in month five, COVID erased the vending venues — rare public data capturing both the ramp-up and the fragility.
Zenn: A Solo-Built Dev Community Transferred to Classmethod 4.5 Months After Launch
Nine days after launch, the solo-built Zenn published "Zenn needs help," fielded offers from more than 20 companies, and was transferred to Classmethod 4.5 months after going live. The decision-making process of a case where "growth was too fast for one person to handle" is fully public.
An individual took over a town bookstore in Chofu. What moved a year-long negotiation was the seller's family
Hitachiya Bookstore in Tobitakyu, Chofu, was handed to an individual buyer in spring 2025 after roughly a year of negotiation. The stalled talks moved once the seller's daughter got involved; the buyer took over from March, resumed about 100 magazine deliveries in April, and reopened storefront sales on June 10.
PAPANAVI: ¥3,000 Logos Repriced to ¥20,000 — From Zero Coconala Requests to ¥1M a Month
A designer specializing in beauty-industry logos went from zero requests for six months on Coconala to ranking #1 in design and ¥1M/month, after specializing and raising prices.
10 years, ~330 LINE stickers, ¥9.79M in cumulative payouts — the month Premium became 70% of revenue
Sticker creator urajo published August 2024 results: a single-month payout of ¥322,211, of which 68.7% came via Premium, far above the 40.7% cumulative share. After about 10 years and roughly 330 stickers, cumulative payouts reached ¥9,790,959. The center of gravity is shifting from one-time purchases to send-count-linked revenue.
A 23-year-old's 17-square-meter crepe shop topped ¥1M/month. Why the profitable owner still called it a "failure"
In November 2021, a then-23-year-old opened a 17-sqm solo-run crepe shop in Osaki, Shinagawa. December sales across storefront, delivery, and ecommerce totaled about ¥500K; some months hit over ¥1M by April-May, with opening costs recovered in 8 months.
From 30 yen in revenue to 8 years later: how running 3 apps in parallel got an indie developer to 200,000 yen a month
Indie development the author started in 2017 earned nothing for five straight years, then 30 yen in year six, 1,000 yen in year seven, 40,000 yen in year eight, and 200,000 yen in year nine. The turning point came the year after shutting down a large-scale service he spent a full year building in 2022, when he set five rules and rebuilt.
A one-time-purchase 2,000-yen iOS app "MT" hit 5 figures in its launch month, 100,000+ yen cumulative in 3 months
A gadget blogger with an engineering day job built "MT," a one-time-purchase 2,000-yen terminal app. It hit 5 figures in revenue in its launch month, and over 100,000 yen cumulative after 3 months. The turning point was "the person writing the review became the person who built the thing being reviewed."
¥9.27M a year on note: from ¥38,500 in January to ¥1M a month, backed by 830,000 social followers
An AI-tool creator with 81,000 YouTube subscribers, 580,000 on Instagram, and 170,000 on TikTok made ¥9.27M on note in 2025. Starting from ¥38,500 in January, we break down the year that shifted him toward the recurring-revenue model of a ¥980/¥1,980-a-month membership with 478 members.
13 games, 700 yen total. Four years to reach the first 8,000-yen payout
A 38-year-old with no prior experience learned Unity and released 13 games over about four years — yet cumulative revenue sat around 700 yen. The turning point came in July 2024, when banner ads were added to his second RPG. 100–200 yen a day for two months finally cleared Google Play's 8,000-yen payout threshold.
Habits Garden: $600/Month, 8,500 Users — the Record of Marc Lou’s Habit App That Never Broke Out
The habit tracker Habits Garden earns $600/month (about ¥90,000) with 8,500 signups. Killing the free plan just before launch raised the paid conversion rate, but developer Marc Lou himself summed it up as "avoid vitamin products."
A ryokan with 80% long-stay guests changed hands in 6 months. Among 4 candidates, the local company that promised "we won't change the name" was chosen
Business Ryokan Masuda in Yokote, Akita had around 80% long-stay guests and was profitable, but owner Masanori Suzuki decided to hand it over after suffering a stroke. He interviewed 4 candidates and, in about six months, transferred it to a local company that offered to keep the name unchanged.