Indie Author Snapshot: The Impact of Adding More Books to an Author's Portfolio

For any indie author who hasn't done so already, there is an invaluable online resource on Facebook known as 20BooksTo50K (R). This indexed Facebook community includes advice and observations from a variety of indie authors, some of whom have become highly successful as self-published writers.

In one survey, members of this community were asked to comment on "that thing" which had made the biggest difference in their success as an indie author. Compiling these responses into categories, there were 101 individual responses to this question. Some respondents provided a list of several key elements which had contributed to their "turning point" as an author, while others cited only that "one thing" which most helped in their career as an author. Of these responses, the majority - over 54% - cited adding more book titles to their portfolio as the single most important element towards their success. The next most popular responses were learning how to do advertising and promotion (30%), and writing to genre (20%).[1]

This was therefore one of the first questions which I sought to explore when reviewing the results from my own, recent data snapshot across a sample of indie authors in the fantasy genre.

As mentioned in a previous post, I surveyed Amazon rankings for 259 titles, and 24 authors - as captured on a single day in June. To convert this snapshot into projected author earnings, I therefore had to convert the Amazon rankings into estimated daily sales, and from sales into revenue.

Fortunately, there is a handy online tool available from KindlePreneur which projects the estimated daily sales, based on the Amazon ranking for each eBook title.[2] Using an equation calibrated against this tool, it was possible to make an estimate for the annual gross income for each author, based on the snapshot in rankings from their respective portfolio of published titles.

A few notes are due for both the merits, and limitations of these projections. First, these are projections only. The estimates are based exclusively on projected eBook sales, and do not include contributions from paperback or audiobook sales - which are usually much smaller than eBook sales for most, but not all indie authors. The totals only reflect sales on Amazon - which is appropriate for the vast majority of the books surveyed. Most of the titles reviewed were Amazon exclusive (KDP Select) novels.

Earnings per sale were projected from Amazon's published rates (35% of the sale price for books less than $2.99, and 70% for books priced at $2.99 or over). These projections ignore the difference between the value of eBook sales, which are based on the price of the book, and KDP Unlimited sales, which are based on the number of pages read. It also ignores any Amazon sales in foreign markets.

Taken as a whole, however, the projections should provide a good sense for trends in author income.

The results from these projections are illustrated in the graph shown, on a logarithmic scale. As should be evident, having more books in an author's portfolio leads to higher author earnings. This relationship is very nonlinear, and nearly quadratic in nature.

A number of alternative regression fits were explored for modeling this trend. The relationship ultimately selected reflects a regression carried out in logarithmic space, with the lowest overall error.

The values projected from this data-match are slightly higher than similar results reported from a poll conducted by Written Word Media, which surveyed over one thousand authors, publishing in a variety of fiction and non-fiction genres.[3]

The results of that survey suggested that the median number of books per author, among those who grossed between $60,000 and $100,000 per year, came out to some 22 titles per author. The projections from the smaller snapshot presented here, would suggest that at 22 titles, the median fantasy author should gross $104,000 per year - slightly higher than the survey from Written Word Media. This would suggest that, on average, the smaller snapshot examined here either tends to overestimate the gross revenue from each novel, or that the authors who were selected might be somewhat biased in favor of better known or more successful writers.  Alternatively, it might also suggest that the fantasy genre tends to provide more sales per title, than other fiction or non-fiction categories.

The precise earning numbers from the projection illustrated above should therefore be taken with a grain of salt.  It's the trends which are most important.

Relationship between the size of an author's portfolio, and the average value of each title. Note that for ease of legibility, the upper portion of this graph has been truncated - omitting some of the higher-performing data points.

Per the regression generated, the average income across all of the books in an author's portfolio will tend to increase as more books are added. In other words, adding books to an author's resume drives more read-through - enhancing the value of the author's entire portfolio.

These projections suggest that the average increase in value for the books in an author's portfolio will follow a nearly linear relationship. Going from five books to ten books, for example, is projected to more than double the average expected earnings per book. But because such an author would now have ten books rather than five, that author's total earnings would increase by a factor of more than four.

The testimony provided in the earlier bar-chart from the authors of Facebook's 20BooksTo50K community, was therefore spot-on. Adding books to an author's backlog of published titles really is one of the most reliable, and powerful tools available towards becoming successful as an indie author.


References:

[1] "Jose's Post." 20BooksTo50K(R) Public Group, Facebook, https://www.facebook.com/groups/781495321956934?view=permalink&id=1034783269961470.

[2] Chesson, Dave. "Amazon Sales Rank Calculator." KindlePreneur, 9 Mar 2020. https://kindlepreneur.com/amazon-kdp-sales-rank-calculator/.

[3] Wolman, Ricci. "Author Income: How to Make a Living From Your Writing." Written Word Media, 22 Oct 2019, https://www.writtenwordmedia.com/author-income-how-to-make-a-living-from-your-writing/.