Books don’t sell in the summer.

Traditionally, the seasonality of book sales is decidedly Southern Hemisphere. Better sock away those December riches, because come July, it’s going to be slim pickings. Back when I was querying agents, summer was advised as both an unusually good and an unusually bad time to do so, because the publishing industry supposedly shuts down until adults come back from beaches and kids go back to school.

Dean Wesley Smith chronicled the “summer slump” here, stating publishing houses punted summer because “it was known that the lowest time for buying books by customers was May through the middle of September.” Despite the ebook/indie revolution, “That has not changed.” Just last week, Digital Book World led an article with “Typically July is one of the slowest months in book publishing.” Google “summer slump” and “book sales” and you’ll find dozens of indie authors advising other indies how to make it through the doldrums without losing hope even as sales (and incomes) slide away into the ooze.

I ran into this same phenomenon myself last year. Great May/June, okay July, then a long, steady slide, until my October was so bad–about $860, as my primary job–I was starting to wonder whether I could keep doing this. Thankfully, a new release turned things around.

Yesterday, someone on KBoards asked whether, in order to avoid the summer slump, they should wait to release their next book until fall. Given what we know, it’s a good question. There’s just one problem.

Books sell just fine in summer.

eBooks do, at least. If you compare the number of sales needed to sustain a given rank on Amazon’s Kindle store, to my eye, it’s the same in July as it was in February. As per the quick and dirty formula I tossed out in that post, to determine how many copies a Kindle title is currently selling, take 100,000 and divide it by its sales rank. Or, to put it another way, rank x sales = 100,000. This rule of thumb comes close whether you’re selling 1/day or 1000/day.

Let’s look at the rank and daily sales of several titles from this July and see how they compare to the numbers from February.

Rank  x  Sales  =  Score ; Estimated February Rank

#95,000 x 1 = 95,000

#12,000 x 10 = 120,000
#2429 x 50 = 121,450
#852 x 120 = 102,240
#819 x 136 = 111,348
#767 x 148 = 113,516
#325 x 280 = 91,000

All right, whole bunch of numbers. What are we actually looking at? An easy way to conceptualize this is to go to the extremes. If Amazon sold so few books that all it took to rank #100 was 1 sale/day, you’re looking at a score of 100 (#100 x 1). By contrast, if it was selling so many books that a rank of #100 required ten million sales/day, your score is 1,000,000,000 (#100 x 10,000,000).

To put it another way, say that it took you 100 sales yesterday to rank #1000. If today it took 200 sales to stay at #1000, that would mean all the books above you were suddenly selling much more, too. Yesterday, your hypothetical score was 100K; today, it’s 200K.

Thus a lower “score” is indicative of lower storewide sales volume while a higher score means more ebooks are being sold on Amazon each day.

Across a broad range of ranks, the average score of those seven books above is 107,793. If anything, more Kindle books are selling right now this summer than were selling in the weeks immediately after the Christmas boom had calmed down.

For ebooks, the “summer slump” is a myth.


Of course, it isn’t quite that simple. While the sample size leaves something to be desired, the most obvious qualification to this methodology is that the “100,000 formula” isn’t a real formula, but more of a rule of thumb. It’s imprecise. Back in February, for instance, it was also true that 10 sales/day would sustain a rank of #12,000, and 120,000 ≠ 100,000.

So if you think I had my original score wrong, and you believe 120,000 was “normal,” then our current score of 108,000 would indicate sales are down by 10% from February.

For most ranks I was looking at in February, however, the score was closer to 100K. Largely in the 95-110K range. To my eyes, the current score of 108K is virtually identical to February. And the number of sales needed to sustain that #12,000 rank was the same in February as it is right now in late July.

That, to me, is the key takeaway: Amazon ebook sales may be down for the summer, but it is not immediately obvious. It’s even possible they’re up. If the slump is so small it can’t be detected, I don’t think it can be called a “slump” at all.


The above table is probably a little confusing, since the “score” is pure abstraction. So here’s another way to think about it. Below, here are the same books above translated into estimated February ranks vs. actual July ranks.
FebruaryJuly – “Winner”
#100,000 – #95,000 – February
#10,000 – #12,000 – July
#2000 – 2429 – July
#833 – #852 – July
#735 – #819 – July
#676 – #767 – July
#357 – #325 – February
If the July rank is worse, that means it would take more sales in July to have climbed as high as it did in February, and thus volume is up now (and vice versa). “Winner” indicates which month seems to have seen higher sales.
Two notes here–I can tell you the February estimates are wrong for the ranks of #10,000 and #2000. The real numbers were more like #12,000 and #2200-2400. Meanwhile, in July, that works out to a rank of.. #12,000 and #2429. Again, it looks like ebook sales volume is heavier in July 2013 than it was in February 2013–but they’re close enough to look pretty much the same.
Share this:

22 Responses to eBooks and the Myth of the "Summer Slump"

Leave a Reply

Your email address will not be published. Required fields are marked *

About Me

I am a Science Fiction and Fantasy author, based in LA. Read More.
My Book Genres