From ¥100 to ¥100,000 a Month in Three Years: The Quiet Compounding of an Ads-Only Tool App

The Published Numbers

Note: the exact download counts, revenue-over-time charts, and user demographics are published in the paid portion of the note (¥1,500), so this article deals only with the figures disclosed in the free portion.

Read This Not as a Success Report, but as a Record of the Plateau

Revenue disclosures from indie developers usually capture only the moment of achievement. Behind a headline like “reached ¥100,000 a month,” the months of silence it took to get there often go unwritten. What makes Wakanao’s note rare as a document is that the author records the starting point exactly as it was: “¥100 a month” and “a good month was around 100 active users.” The vast majority of indie apps die at this stage, and it is fair to say that how you define the ¥100-a-month period is everything in this playbook.

The app’s name is not disclosed; the genre is described only as a “tool app.” Two monetization channels were tried, ads and affiliate, and the note is structured around sharing “how much revenue could be generated mainly from ads out of those two.” The pillar turned out to be AdMob, which reportedly delivers relatively high ad rates despite the app being a tool app. Looking back on the three years, the developer’s own words are: “Watching an app I struggled to raise grow feels like watching my own child grow. It brings me great joy.” There is no talk of flashy strategy anywhere in the free portion.

Decomposing the Gap Between 1,000x and 100x

Placing the two published multiples side by side reveals an interesting mismatch. Revenue went from ¥100 to about ¥100,000 a month, roughly 1,000x. MAU, meanwhile, grew “more than 100x.” User growth alone cannot explain the revenue growth, which lets us infer that ad revenue per user improved at the same time.

The passing remark about “relatively high ad rates despite being a tool app” is also important information, however casually written. Tool apps generally have short session times and little ad inventory, so eCPM tends to stay low. If high rates are being achieved there, the app has likely landed in a category where advertiser bidding is strong. A genre where users’ search intent sits close to some purchase or contract. With the same MAU, ad revenue can vary severalfold depending on the genre.

For an ad-model app, this multiplication is the essence of the business. If MAU grows 100x and revenue per user grows 10x, revenue grows 1,000x. The former is driven by in-store compounding (discussed below). The latter by optimizing ad formats and placements and by AdMob-side rate fluctuations. When Wakanao writes about having “continued regular maintenance,” that work surely included not mere life support but continually adjusting this second variable. The specifics of what was changed and when, though, are in the paid portion, what the free portion lets us confirm is only the numbers at both ends.

The Logic of Growing 100x by “Just Leaving It There”

As a path to 100x MAU with no marketing and no viral moment, the explanation consistent with the free-portion information is the compounding of in-store search. Tool apps are discovered through clear search intent, queries like “how to do X” or “X calculator.” Right after release the app sinks to the bottom of search results, but as a small number of users accumulate reviews and usage history, rankings and search positions inch upward, exposure increases, and more usage accumulates. Each turn of this cycle takes months, but once it starts spinning, it rarely spins backward.

This is the same time-as-an-ally playbook as the Kindle publishing shelf and the stock photo inventory. A paid app that doesn’t sell early on becomes financially and psychologically impossible to continue, but with an ad model, revenue tracks MAU as long as the app “keeps being used.” Whether you can regard the ¥100-a-month period as a “measurement period” rather than a “failure” is the watershed of this playbook.

What This Case Cannot Verify

The limits of this case as a document should be stated plainly. Because the app’s name is undisclosed, third parties cannot check its actual store rankings, reviews, or competitive situation. The revenue chart and download counts, meanwhile, are in the paid portion, so the shape of the curve between “¥100 and ¥100,000 a month”, whether it grew linearly or bent at some update or initiative, cannot be verified from the free portion. All this article can work with is two points: the starting point and the present.

And a caveat of a different kind: the note itself is sold for ¥1,500, revenue disclosure becoming a revenue source in its own right, a standard second act for indie developers. This does not undermine the credibility of the numbers, but it is worth keeping in mind that the granularity of disclosure is designed around “what can be sold.”

With that said, the ¥100,000-a-month milestone sits close to the realistic ceiling for “ads only.” Given AdMob’s effective eCPM, ¥100,000 a month requires substantial impressions (that is, a solid MAU) and the standard next moves from here are adding paid features (IsTalk’s subscription) or going multi-app (Dokozono’s ¥50,000 a month). Public cases of a single tool app growing to ¥300,000 or ¥500,000 a month on ads alone are scarce, and this case too lives within the constraint that “the upside of ads alone equals the upside of MAU.”

Conditions for Reproducing This

Whether you can trace this curve is decided less by technical skill than by the profit-and-loss structure. Only someone with a day job, near-zero server costs, and updates that fit within the bounds of a hobby (in other words, someone who can build a structure in which the ¥100-a-month period costs them nothing) gets to collect the compounding three years later. For people who make exit decisions based on early revenue, or who want to rush monetization and lead with paid features, this playbook is unsuitable from the start.

The other condition is genre selection. In-store compounding only spins for “apps that people search for.” Choosing a plain but persistently searched tool app, rather than an entertainment app chasing social media virality, was, seen from the outcome, the single biggest decision. Conversely, leave an app with no search demand on the store for three years and the first 100 users who seed the compounding will never appear. This playbook is not “wait and it grows”. It is a structure where “the waiting pays off only when you have placed something that keeps being searched for.”

Related Reading

• Dokozono’s ¥50,000-a-month apps — the same “stack small things” playbook
• IsTalk at ¥2.5M a month — the opposite playbook of working backward from ad inventory