Solopreneur case studies — 6/11
Solopreneur and side-business cases
121–144 of 256
90 quiz apps, 8.2 million downloads, ¥20 million+ in revenue — the real picture of mass production, where only 2 in 10 hit
A solo developer who specializes in quiz/personality apps released 90+ titles over four years, reaching 8.2M downloads and over ¥20M in revenue, while admitting flops like a 5,000-download "romantic type" quiz.
Website Investing: Paid Subscriptions Stalled at 70 — a Free Tier in Front Led to $7,500/Month and a Six-Figure Sale in Seven Months
Richard Patey's paid newsletter, charging $49/month, plateaued at 70 paying subscribers. After moving to Substack in May 2020 and putting a free tier in front, it reached 100 paying subscribers, 2,700 free subscribers, and $7,500 in monthly revenue seven months later — and sold for six figures.
A tech-book ranking site built from 300,000 Qiita articles hit 100,000 yen in revenue three weeks after launch
A solo developer aggregated roughly 300,000 Qiita articles via API to build a ranking of 4,000 technical books, and the site earned 100,000 yen within three weeks of launch. The turning point was setting aside his own passion project after a prior failure and rebuilding the concept from scratch by studying and copying successful examples.
A stay-at-home mom's blog, year two: 203,000 yen annual revenue. PV grew 19x, revenue grew only 5.8x
The blog "Delako Blog" launched in March 2021. Year one: 26 posts, 4,050 PV, 34,700 yen revenue. Year two: 53 posts, 76,658 PV, 203,000 yen. This article examines from the numbers why revenue grew only about 5.8x even though PV grew about 19x.
A crypto side-hustle app went from ¥300,000/month to a few thousand yen. 20,000 installs, ¥18,000-per-referral, and how it vanished
A manufacturing employee's hobby crypto demo-trading app "BitVirtual" hit 20,000 installs and ¥300,000/month during the 2017 boom, with exchange affiliate payouts up to ¥18,000/referral — then collapsed to a few thousand yen a month a year later.
A trivia TikTok channel earned about ¥9 million over two years — average monthly income of ¥400,000, and RPM collapsing into the ¥20s
A trivia-focused TikToker disclosed 24 months of earnings: about ¥9 million total, ¥400,000 average monthly, but RPM has fallen to around ¥20 since April 2025.
She put all ¥50,000 of her sales balance into ads. How a handmade artist's monthly sales went ¥70K → ¥590K → a ¥2M peak
Surume, a jewelry artist on Creema, put her entire ¥50,000 balance into promotional ads and watched monthly sales climb ¥70K → ¥140K → ¥290K → ¥590K. Peak monthly sales hit ¥2M, with 3 straight months over ¥1M recently.
RecordJoy: Bought for $10K, Sold a Year Later for $20K — What a Micro-Acquisition Actually Looks Like for a Former Netflix Engineer
Michael Lin, a former Netflix engineer, acquired the zero-revenue recording tool RecordJoy for $10,000 in 2021. By adding a payment flow and growing through AppSumo, he reached 20,000 users and about $1,000 MRR, then sold it for $20,000 in early 2022 — 2 weeks after listing, with 20+ offers.
A Notion-to-spreadsheet sync add-on hits $8,400 MRR: how it reached 400+ paying customers in two weeks
Leandro built Notion2Sheets in two weeks after Notion's API launch, growing it to 40,000 installs and $8,400 MRR. Killing the free plan was the turnaround.
About 4 Months From Decision to Taking Over a Fukuoka Tutoring School — a Corporate Manager Who Brought a Proposal to the First Meeting
Mr. Suzuki (a pseudonym), who worked as a manager in a major manufacturer's overseas business division, decided in January 2024 to go independent through M&A. About four months after starting his search on Batonz, he had resigned, signed the M&A contract, and become president, taking over a Fukuoka-based individualized tutoring school in August of the same year. The decisive factor was bringing a proposal to the first meeting and pitching improvement ideas.
A senior-care info site earning ¥17,200/month in profit sold for ¥1.4 million — inside a valuation of 81 months of profit
From Rakko M&A's analysis of 1,050 completed site sales, one deal stands out: a nursing-home info site earning ¥17,200/month in profit and roughly 30,000 PV sold for ¥1.4M — a multiple of ~81 months, 4.6x the survey average of 17.8 months.
Five years on one app, then 30 apps in ten months. The portfolio pivot that reached $22,000/month
Max Artemov, an iOS engineer with 8 years of experience, spent over five years failing to grow his first app, a calorie counter. In February 2025 he switched from "polish one app" to "ship many," and in 10 months reached 30+ apps generating a combined $22,000 MRR.
TalkNotes: Sold for $200,000 in 11 Months — Why the $7,000-MRR AI Voice-Memo App Chose an All-Cash Deal
Nico Jeannen sold his AI voice-memo app TalkNotes for $200,000 just 11 months after launch — turning down a higher $300,000 earnout offer for cash up front.
A nail salon with 1,500 customers and 10 staff was taken over for 2 million yen. What an administrative scrivener prioritized above all
An administrative scrivener (gyoseishoshi) who went independent handling subsidy application proxy work acquired a nail salon in Mie Prefecture for 2 million yen. With over 1,500 customers and 10 staff, the top priority for the takeover was "retaining the employees." After visiting the site 3 times to interview every staff member individually, the business turned profitable by the third month.
Launch Fast: Built in 48 Hours, $15K/Month in 30 Days — Inside the Non-Technical Founder’s Path to $450K/Month
A non-technical founder built an MVP in 48 hours and grew Amazon-seller tool Launch Fast to $30K MRR after equity-swapping for access to a coaching program's audience.
Peak Monthly Sales of ¥1 Million on minne. A Former Designer Turned Handmade Artist Explains the Craft of "Photos That Sell"
Tokuda Konoka, a former interior designer turned handmade artist, disclosed monthly sales of ¥550,000 at the two-year mark and a peak of ¥1 million on minne. The core of those sales was product photography — and the practical value of this case lies in how she articulates the technique: natural light, white backgrounds, and model shots.
Warary!: A Comedy Live Show Search Service Built Solo for 2.5 Years, Then Sold to a Company
A case where the comedy live show search service "Warary!" was run solo for two and a half years and sold to a company in 2020. The sale price is undisclosed, but the developer has published his rule of thumb — "monthly profit x 24 months + goodwill" — along with his criteria for deciding whether to sell or keep going.
A 10,000-Subscriber YouTube Channel Earns ¥30,000/Month in Ads. Why Keep Going? "¥100,000 Sponsorships and My Own Products"
Web-development YouTuber Shogo published his income at the 10,000-subscriber mark. Ad revenue averaged about ¥30,000/month (nine months of actual monthly figures disclosed), and his own conclusion is that "ads alone cannot pay the bills." The real earners were corporate sponsorships at ¥100,000 per video and his own products, which earn tens of times more than ads.
Easy Folders: One Chrome Extension, $3,700 MRR and $42,000 Lifetime Revenue in 6 Months — a “Fill the Gap” Structure
Edmund Yong's Chrome extension "Easy Folders" hit $3,700+ MRR and $42,000+ in lifetime revenue 6 months post-launch. Running costs are just his Mailgun bill. This piece breaks down a structure built on filling a $9/month gap: ChatGPT's missing folder feature.
Zen Arbitrage: From Dumpster Diving to $90K/Month — a Book-Flipping SaaS, a 3-Year Plateau, and a Sale to a $66M Roll-Up
Zen Arbitrage, a book-flipping tool, launched in 2015 on $14,000 in development costs, sold out 100 slots at $97/month in 90 seconds, and grew to $90K in monthly revenue and 750 members. After a three-year plateau at $30K, it sold in 2022 to Carbon6, a roll-up buying up Amazon tools. The founder candidly shares even his due-diligence failures.
Resale Arbitrage, Month Three: ¥267,000 in Sales, ¥44,000 in Net Profit. The 16.3% Margin Cost Structure of a Reselling Side Business
Real data from month three of a side-business resale operation: sales of ¥267,389 against costs of ¥223,868, for a net profit of ¥43,521 (16.3% margin). Sourcing between day-job hours is uneven, and over 80% of revenue disappears into cost of goods and fees — the structure of physical-goods reselling, disclosed in a beginner's honest numbers.
NoteForms: A Notion Form Connector Built in 3–4 Days Grows Into $37K/Month — 18 Months of Solo Support
Julien Nahum built NotionForms in 3–4 days after Notion's API launched. It became NoteForms, a $37,000 MRR business, after prices rose from $15 to $24.
AI Generation × Adobe Stock: ¥500,000 a Year. Twelve Months of Real Data Behind the ¥42,000/Month a Salaryman in His 40s Built on Weekends Alone
Rossin, a company employee in his 40s, sells Midjourney-generated images on Adobe Stock and published his 2025 earnings month by month: ¥501,834 for the year (¥41,819 monthly average). The peak was ¥56,000 in December — seasonal assets drive sales. Three years of continuous operation, working weekends only.
SEO Tool TopicRanker Sold to Portfolio Operator iTrinity: A Division of Labor Where "Individuals Build, Specialists Grow"
TopicRanker, an SEO tool that finds keywords where weak competitors rank, was launched solo by SEO practitioner Dmitry Dragilev and sold to SaaS portfolio company iTrinity — a microcosm of the micro-SaaS market's growing split between building and operating.