A solo operator earning 102 million yen a year. How an affiliate marketer who fell from 75 million to 50 million broke his own record

Individual income disclosures usually end with a single month’s screenshot. What makes Kuroneko-ya’s “Revenue Reports” category unusual is that it has left a multi-year record, as articles, spanning 2017 through 2021. And that trajectory is not a straight line upward. He lost two-thirds of his income over three years, 75 million yen → 69 million yen → 50 million yen, before it snapped back to 102 million yen.

The disclosed trajectory of annual income

What’s disclosed is figures on an annual basis. Month-by-month progression is not disclosed as a rule. The 8.5 million yen this article treats as the monthly-equivalent figure is the average obtained by dividing the 2021 annual income of 102 million yen by 12. It does not mean that amount actually landed every month (in fact, September saw an outlier month of 12 million yen).

He entered affiliate marketing in 2014 and incorporated in 2016. In November 2017 he also reported that cumulative sales since incorporation had passed 130 million yen. He has zero employees. In his own words, he runs this “solo, with almost no outsourcing,” which is why these are written as personal income rather than as company revenue.

His background isn’t unusual either. He worked as a company employee for a year but quit due to workplace harassment, then aspired to be a writer, though the writing business didn’t generate sales. He then repurposed the writing skills he had left over into affiliate marketing. That’s the order of events. He describes himself as “low-effort by nature” and writes that he hasn’t attended seminars.

What happened during the three declining years

Regarding 2016, Kuroneko-ya writes, “Long-form SEO was overwhelmingly dominant that year.” It was a period when long, detailed articles of 1,500+ characters were favored in search, and by the latter half of the year he had reached a pace of 9 million yen a month. He also tried using outsourced writers, but it failed, and from then on he settled into writing every article himself, running everything from site-building to ad operations solo.

The collapse began in February 2017. After the Fred Update, monthly income fell to 3–4 million yen, roughly a 60% drop from the peak. The year still landed at 69 million yen, but the latter half’s level was an entirely different world from the year before.

He cites three causes for the 50 million yen result in 2018. He was able to land “minor hits” at the 300,000-yen-a-month scale, but failed to build new large sites earning 1 million yen or more a month. Sites he had grown in the past gradually declined, and he couldn’t build replacements in time. And sites damaged by the 2016–2017 updates fully died off in 2018. In his words, “many sites died gradually”. He describes it as genres with strong competitors sinking first. At the same time, he also writes that a roughly 100-article site he started in early 2018 “is still steadily earning nearly 300,000 yen a month”, showing that in less competitive genres, lifespan can be much longer.

Tax burden is also on the record. In 2018, he paid 8 million yen in estimated tax and another 8 million yen in year-end tax, for an effective tax rate (including consumption tax) of about 40%. Even at 50 million yen in annual income, what’s left in hand is roughly 30 million yen.

The decisive move: shifting the foundation of revenue from a third party’s evaluation to his own readers

The 102 million yen in 2021 is not simply an extension of the same business. In his annual report, he cites three factors.

First, a major increase in output volume. He launched a newsletter built around a free course as its entry point, automating everything from education to sales using a step-mail (drip) function. Subscribers exceeded 4,000. The design is a single funnel: “capture attention on social media, reinforce it on the blog, then educate and sell via the newsletter.” On the audio platform Voicy, he reached 7,000 followers.

Beyond volume, there was the development of a major new product. He created video seminars plus text courses priced at over 100,000 yen and sold more than 500 units. Previously his lineup centered on products under 100,000 yen, even a mini course on note priced from 980 yen could bring in over 1 million yen in profit per product, so this was a step up in price tier. In September he hit a peak of 12 million yen in a single month.

And in distribution, daily posting on Twitter. He maintained a pace of gaining 3,000 followers a month, creating a state of constantly being visible.

Doing the math: 100,000 yen × 500 units alone amounts to roughly 50 million yen. That’s a single product line generating an amount equivalent to his entire annual income in 2018. It’s not a stretch to say a substantial portion of the 102 million yen came from course sales.

Why the shift to course sales worked

The structural difference is where the business is built.

SEO affiliate marketing is built on top of someone else’s asset: the search engine’s evaluation. If the landlord changes the evaluation criteria, revenue can drop 60% the following month. The figure of 9 million yen → 3–4 million yen a month in February 2017 is exactly that fragility, recorded as data. And because he runs solo with outsourcing not really working for him, there’s a hard ceiling, his own writing capacity, on how fast he can rebuild what was lost by producing more sites. Failing to build a replacement in time in 2018 is the result of hitting that ceiling.

Course sales are built on reader assets that belong to him: 4,000 newsletter subscribers, 7,000 Voicy followers, and a Twitter following growing by 3,000 a month. Search rankings can shift, but the list doesn’t disappear. On top of that, the product is digital, with near-zero replication cost. Since he doesn’t outsource, there are essentially no variable costs, so revenue converges almost directly into personal income. Being able to write “personal income, not company revenue” is a direct consequence of this cost structure.

One more thing shouldn’t be overlooked: the three declining years of affiliate marketing themselves became the raw material for the courses. His hands-on experience since 2014, the experience of hitting 9 million yen a month, the experience of being knocked down by algorithm updates. These are contents competitors can’t assemble in the short term, and they’re also the basis on which a 100,000-yen price point holds up. The decline was a loss as a business, but it became inventory as content.

Not everything worked

Even within the 2021 report, the tactics vary in how well they worked. He writes that Voicy was a struggle early on, and he only became proficient after more than 100 episodes. Instagram was still at a trial stage with reels, an ongoing search for the right format. It seems more accurate to read this not as “adding more channels worked” in itself, but as: there was a newsletter serving as the receiving vessel that made “education and sales” efficient, and on top of that, he added more entry points feeding into it. That’s what worked. The fact that he places the purpose of Voicy and Twitter as “narrowing the distance with existing users rather than acquiring new ones” also supports this ordering.

The limits should also be stated plainly. Income for 2019 and 2020 is not disclosed. How he transitioned from 50 million yen to 102 million yen along the way cannot be traced. Also, because this business model is “teaching what you earned,” the product’s power depends on his track record continuing to be updated. This is a structural characteristic that can be read from the disclosed numbers, not something the original source itself states. He himself writes, “only those who keep challenging themselves can survive.”

What can be taken out, and what can’t

What can be taken out is the design. Owning your own reader list separate from acquisition channels. Automating education and sales with step-mail, decoupling working hours from revenue. Raising your unit price, rather than stacking products under 100,000 yen, selling 500 units at over 100,000 yen reaches the same amount with far less effort. And choosing products with zero replication cost while not increasing outsourcing. Most of the reason a solo operator reached 100 million yen lies in this cost structure.

What can’t be taken out is just as clear. The long-form SEO environment of 2016 no longer exists. And above all, without the track record of having earned 75 million yen, a 100,000-yen course wouldn’t sell 500 units. The reproducible part of this case is “how to monetize after you’ve built a track record,” not “how to build the track record.” The first seven years cannot be substituted by the three tactics described in the later article.

Related reading

• Hitode’s blog operation — a different answer to the same question of how to coexist with search dependence
• Photo AI and levelsio — an overseas example of a solo operator converting follower assets into a product