Solopreneur case studies — 2/9
Solopreneur and side-business cases
25–48 of 201
From ¥100 to ¥100,000 a Month in Three Years: The Quiet Compounding of an Ads-Only Tool App
The tool app built by Wakanao, a solo developer from Hokkaido, earned about ¥100 a month at launch. Over three-plus years of persistence, MAU grew more than 100x and revenue reached ¥100,000 a month from AdMob ads alone. A record of the growth curve of an app with no paid features and no marketing — one that simply stayed on the store.
Four Rental Spaces Generating ¥360,000 in Monthly Profit. 30% Fees, ¥450,000–700,000 Upfront — the Going Rates of the Hourly-Rental Market
Serial entrepreneur Kenji Sato published both his track record — four rental spaces producing ¥360,000 in monthly profit — and a market-wide picture of the going rates. Hourly rates cluster at ¥3,000–6,000, platform fees run 30–35%, upfront costs are ¥450,000–700,000, and roughly 30% of operators lose money in year one. A document that lays out the industry's P&L template before you enter.
Screenshot-Annotation Tool InstaCap Sold for 6x Revenue to a Serial Entrepreneur: Why It Beat the Standard Micro-SaaS Multiple
InstaCap, a tool for annotating and sharing screenshots, was sold by founder Samee Hassan to serial entrepreneur Joe Speiser at 6x revenue. Material for thinking about what conditions produce a multiple above the standard 3–5x range.
Shopify App Portfolio Plug in Useful, 37,000 Users, Sold to SureSwift: An App Business Built by "The SEO Guy"
Plug in Useful, a portfolio of Shopify apps run solo by Daniel Sim with 37,000 users, was sold to SureSwift Capital, a serial acquirer of SaaS businesses. A real example of a specialist-turned-founder building an ecosystem by turning his own SEO expertise into apps.
Sidekiq: Open Source to $7M+ a Year, Solo — the Finished Form of a 20-Year “OSS + Paid Edition” Strategy
Mike Perham, creator of Sidekiq, the open-source background job processor for Ruby, has run a free-OSS-plus-paid-Pro/Enterprise model entirely alone and grown it past $7M (about ¥1.05 billion) in annual revenue (in 2023 he said it was "closer to $10M than $1M"). The pinnacle of commercializing OSS with zero employees.
Two Real Records of Renting Out a Home Parking Space — ¥741/Month Average in the Countryside, ¥4,500/Month in the City. An akippa/Toku-P P&L Breakdown
Two people rented out their home parking spaces via akippa and Toku-P. A regional residential street (20 min walk from the station) saw 32 days of use in a year — ¥741/month average, ¥2,164 best month. The urban case filled 3–4 days a week for about ¥4,500/month. Measured values for a "zero-investment, zero-effort" side hustle where fees (akippa ~54% / Toku-P 30%) and location decide everything.
Streets of Rogue: An Indie Game Built on $18,000 Sold for Roughly $6.5M — the Six-Year Story
Streets of Rogue, a roguelike made by a solo developer with $18,000 of his own money, sold over one million copies, generated $8M in lifetime revenue, and was acquired by tinyBuild for $6.5M in June 2021.
Why We Buy: Subscribers Up 1.4x, Revenue Up 3.3x — the Structure Behind a ¥150M Year in 2024
Marketer newsletter "Why We Buy" grew from 50,000 subscribers and $300K in annual revenue to nearly 70,000 subscribers and roughly $1M. This piece examines the mechanics behind subscribers growing 1.4x while revenue grew 3.3x.
Visual Quiz Builder: A Shopify Diagnostic-Quiz App Sold for $1M With Zero Ad Spend — the Quiet Growth
Visual Quiz Builder, which adds "find the product that fits you" diagnostic quizzes to Shopify stores, was sold to Alleyway Capital for around $1 million while spending almost nothing on advertising or traditional marketing. A record of reaching an exit purely on organic growth inside an app store.
Backlink-Design SaaS SEOJet Doubled Its Price in the Year Before the Sale — What the Prep Work Looked Like
Founder Adam White sold SEOJet, a tool for designing backlink anchor-text profiles, for double the price he originally expected, by doing extra groundwork right before the sale. A real example showing that "the year before you sell" moves the sale price more than anything else.
SearchSEO Sold for About $300K: The Exit and the Limits of a "Gray-Hat SaaS"
SearchSEO, a SaaS that manipulated search-result click-through rates with simulated traffic, was sold by founder Martin Delannoy to individual buyers for around $300K (about ¥45M). Material for thinking about the pricing and timing of a business carrying terms-of-service risk.
Justin Welsh: $12.5M Cumulative With One Person and an Outsourced VA — a Solo Business Portfolio With 90%+ Margins
Justin Welsh, a former healthcare-SaaS sales executive, went independent in 2019 and built a one-person business portfolio of social-media content, digital courses, and a newsletter, generating over $2M a year and over $12.5M cumulative (self-disclosed). Zero employees, only a part-time VA, and margins above 90% — a defining example of "management without hiring."
Podcast Clout, Born as a PR Agency's Internal Tool, Sold at 3x Revenue to a Pair of Individual Investors
Podcast Clout, a SaaS database of podcast shows, began as a tool the founder built for her own PR agency's work before it was productized — and it ultimately sold at 3x revenue to two individual investors. "Productizing an internal tool" remains one of the most pre-validated ways to start a company.
WordPress Theme Craftsman Array Themes Joins WP Engine: The Negotiation Lessons of "Selling After Saying No, Again and Again"
Array Themes, a one-person WordPress theme studio, turned down multiple acquisition offers before finally selling to WordPress hosting giant WP Engine. A case where the seller's selectivity — who to refuse and who to say yes to — takes center stage.
10 apps over 8 years, 30,000 yen a month. The peak was 2021 — why an indie developer's ad revenue turned downhill
A 50-something engineer at a manufacturer published 8 apps for iOS and 2 for Android. Steady ASO work drove growth until 2021, when he peaked at nearly 50,000 yen a month. After he stopped building new apps in 2022, revenue declined, and it now sits around 30,000 yen a month.
Three months of real numbers from a paid note magazine: subscribers 8 → 5 → 15, revenue ¥16,000 → ¥2,500 → ¥8,000
An individual with 1,500 followers and ¥80,000/month in note sales launched a ¥500/month subscription magazine. Month one: 8 subscribers, about ¥16,000. Month two: 3 cancellations drop it to 5 subscribers and about ¥2,500. After cutting the update frequency from twice a week to once and raising the price to ¥700, month three recovered to 15 subscribers.
Meal-Prep Subscription Workweek Lunch Sells to a Peer: A D2C Media Business Built on the Never-Ending Question of "What to Cook"
Workweek Lunch, a subscription delivering meal-prep menu plans, was built single-handedly by founder Talia Koren over seven years and sold to fellow meal-prep business MealPrep On Fleek. A case of turning the eternal question of "what do I cook this week?" into subscription revenue.
The Reality of LINE Sticker Side Income: ¥1,807 in 2 Years, ¥1,502 in 5. Two First-Person Records Map the "Distribution of the Dream"
Two people who made and sold LINE stickers "casually" share their books: Pota earned a cumulative ¥1,807 in 2 years; the Run household earned about ¥1,502 in 5 years (monthly payouts ranging from ¥2 to ¥39). A record of the real baseline for entering the sticker side hustle — often billed as "make it once, it sells forever" — with zero promotion.
VC Industry Newsletter StrictlyVC Sells to TechCrunch: Ten Years of an "Industry Insider" Becoming Media
StrictlyVC, a venture-capital industry newsletter started single-handedly by former TechCrunch reporter Connie Loizos, was acquired by her old employer, TechCrunch. A rare shape of deal where an industry insider's personal newsletter gets imported back into the industry's biggest media outlet.
From ¥2,000 to ¥20,000 a video: three years of video editing, and the turning point of "direct sales after the director quit"
An individual on leave from an engineering job moved into video editing with no prior experience. The first gig paid ¥5,000 a video; the cheapest paid ¥2,000 for six hours of work. Of eight clients, all but one fell through — until in June 2023 he pitched the one surviving client directly and converted it into a direct contract. The rate rose from ¥10,000 to ¥14,000 to ¥20,000. He now earns ¥200,000–300,000/month from that single client.
Apple froze his account, revenue dropped 75% — the comeback: 30 apps mass-produced into $60,000/month
Viktor Seraleev lost 75% of his revenue overnight when he relocated in 2022, then had Apple freeze his developer account and his bank account frozen too. He abandoned swinging for a single hit and switched to a "build 10 apps, no matter what" rule — now running 30+ apps at over $60,000/month.
An Engineer's Side-Business Rental Spaces: ¥7.5 Million in Year One Across Three Locations. Measured Unit Economics of a 25m², ¥450,000-Upfront Space
Hirosena, a web engineer, has run three rental spaces in Tokyo and Saitama as a side business since 2023, earning about ¥7.5 million in side income in year one. His published Saitama location (25m², capacity 10) cost ¥450,000 upfront with rent of ¥91,600, and averages ¥250,000 in monthly revenue and ¥68,500 in monthly profit, with payback in about six months. Measured data on the rent-then-sublet-by-the-hour model.
Free-Template Site SlidesCarnival Sold to Canva for €20K/Month: What a One-Person Distribution Site Can Reach
SlidesCarnival, a free presentation-template site run single-handedly by Spanish designer Jimena Catalina Gayo, generated €20,000 (about ¥3.3M) a month in ad revenue and was acquired by Canva, the biggest name in design platforms. Like html5up before Carrd, it shows a "free-giveaway audience" being bought by a major company.
A stock photo side hustle: ¥28,284 in half a year — the breakdown across 5 sites, and the structure of "income with no turning point"
A sole proprietor who left salaried work at 40 and moved to the village of Hakuba disclosed his first-half 2025 stock photo results: ¥28,284 total (an average of ¥4,714/month). We break down the breakdown across 5 sites and the operating design behind a slow-and-steady income stream with no dramatic turning point.