It’s now been two years since the release of my book Building a Second Brain. It has already reached and surpassed every goal I had for it, with 250,000 worldwide sales and many new countries and languages still to come.

On this occasion, however, I want to answer a longstanding question that is only just starting to come into focus: Has the success of this book grown the underlying business?

This was one of the most important rationales I had for writing a mainstream, traditionally published book in the first place (which I first formulated in March 2019) – to create a “loss leader” and promotional vehicle for the other products our company sells, such as courses.

With two years of hindsight and data, we can start to arrive at some answers. Let’s approach it through a series of questions.

Did the book grow our audience?

My first hypothesis was that the success of my book would significantly grow our audience. Looking at the growth trajectory of our email list over the past five years allows us to compare the period before the book and after it (the vertical line is the book’s publication date):

The graph above shows a clear inflection point right around the time my book was released, strongly suggesting it made a big impact. 

In the two years preceding the book’s release, our email list grew by 42 new subscribers per day on average (from 16,000 to 46,000 subscribers). In the two years since the book’s release, it’s grown by 108 new subscribers per day on average (from 46,000 to 125,000).

That represents a 2.6x acceleration in new subscribers per day on average. In a timeline where the book never existed and the previous growth rate remained constant, we would have ended up with 77,000 subscribers today, instead of 125,000, which means there are 48,000 people on our email list that likely wouldn’t be there if it wasn’t for the book.

Looking at social media, I compared our following on each platform where we have a presence between March 2020 (when I signed the publishing contract for Building a Second Brain) to March 2024 (when I signed for my next book).

We’ve seen tremendous growth across every platform, including 180x on LinkedIn, 147x on YouTube, 24x on Facebook, 16x on Instagram, and 13x on Twitter/X. Overall, the Forte Labs audience grew 28x over these four years, an incredible result.

In this chart showing the trajectories of each platform over the last two years, you can clearly see that they fall into three distinct groups: the low-effort platforms where we only repurpose content from elsewhere (Facebook, Instagram, LinkedIn), the high-effort platforms we focus on (Twitter/X and the newsletter), and then YouTube, which stands on its own due to the power of the algorithm in continuously finding new audiences for our videos.

I can definitively say that my book succeeded in massively growing our audience. There were several additional factors, such as the major investments we made into YouTube over the same time period, and pandemic-fueled growth, but I still conclude that most of this wouldn’t have happened in the absence of my book.

Next, I’ll turn my attention to whether all those new followers and subscribers actually led to growth in the underlying business.

What is our audience worth?

Although there are a lot of intangible or difficult-to-measure benefits of writing a bestselling book, the one I’m interested in most is the financial return-on-investment. If the numbers don’t make sense, then everything else is a wash.

If there are 48,000 subscribers on our email list who wouldn’t be there otherwise, I wanted to calculate how much revenue they would theoretically add to the business. I know our Lifetime Customer Value is $720, so assuming we can convert 10% of those subscribers to customers, that suggests $3.4 million dollars in potential revenue.

Now, realizing that potential revenue is an entirely different question. In late 2023, we stopped offering live cohorts, which were our primary revenue source up until then. This made it significantly harder to monetize all those new followers, forcing us to depend on lower-priced products such as self-paced courses.

Looking at the onboarding survey for those courses, the main ways people found out about us are YouTube (this includes other people’s channels as well as our own), and in second place, my books.

Cross-referencing these referral numbers with our course sales over the past couple years indicates that about $486,000 of our revenue came by way of books, which suggests that we’ve only successfully realized 14% of the potential revenue of this new, larger audience.

Did my bestselling book turn out to be a financial failure?

My strategy with the BASB book was to treat it as a “loss leader” in favor of monetizing via courses, and now I have the chance to determine whether that’s panned out.

Looking only at the book itself, we’ve spent $1.13 million dollars ($570,000 on staff costs plus $560,000 on everything else) on its creation and promotion so far. On the revenue side, book advances have added up to $498,000, and if we add another $486,000 in course referrals, that adds up to $984,000 in total book-related revenue. Which means five years after the start of the project and two years since publication, we’ve yet to break even and are still about $146,000 in the red.

Adding YouTube to the picture, we’ve made $840,000 (via Google AdSense, sponsored videos, and course referrals) and spent $576,000, for a profit of $264,000. Our YouTube videos have been both funded by book revenue and inspired by the content of the book, so I doubt this performance would have been possible without the book. Considering the book and YouTube channel together, they’ve made $1.8M and cost $1.7M, slightly more than breaking even.

The great confounding factor in this entire analysis is that we are in the midst of an “online course winter,” as the immense surge of enthusiasm for everything digital that the pandemic unleashed is now giving way to an exodus, as people want to spend their time and money elsewhere. Nearly all course creators I know are struggling, and in a couple of years, we may see all these numbers turn around.

But if I’m being brutally honest with myself, the financial picture of my book has thus far been pretty mediocre. 

Despite its runaway success in terms of copies sold, I made three major mistakes that are making it difficult for us to capitalize on that success:

1. I spent too much money in the leadup and initial launch of the book, putting us deep into a financial hole that is now taking a long time to climb out of (I probably should have been more conservative with my spending and investments from the beginning).
2. We killed our flagship program and main source of revenue just as our following was exploding (it probably would have been better to change and adapt the live cohort-based course to the needs of readers, rather than killing it completely).
3. We didn’t create a clear pathway from reading the book to taking a course that picked up where it left off (our self-paced Foundation course is largely an alternative to the book in video form).

Essentially, I assumed and hoped that the “rising tide” of the book would “lift all boats” in the business, but without a clear pathway to a profitable course, and no funds held in reserve that would have helped us to build that pathway, we’ve been unable to translate much of the flood of interest we’ve received into profitability.

The big open question for the future is whether subsequent books will change this equation. I’ve already noticed that the short follow-up companion The PARA Method, which I released just a year after Building a Second Brain, has been almost pure profit, since it takes advantage of all the infrastructure and the following created by the first book and thus required very little new spending. 

My next book, on the practice of annual life reviews, will come out in the fall of 2026 and represent my first major title since BASB, and thus the first true test of whether my book writing efforts can be profitable long term.

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