Book Sales Info (and Guppy TV)

One question I get asked a lot is how the release of a new book affects sales of my backlist.  I’ve said before that the only factor I’ve seen consistently and clearly improve sales of a book is the release of the next book in that series.  I figured with Red Hood coming out, I could indulge my inner graph-geek and share a little data to back that up.  (For legal/contractual reasons, I can’t share the actual numbers.)

Let’s start with the princes series.  The green line represents sales of Red Hood’s Revenge.  You can see the first two books in the series were selling fairly steadily.  Column 4 marks when copies of Red Hood started showing up in stores.  Column 6 is the official release week.

Sales of the older books are nowhere near as good as the new one, but those sales do increase significantly when the new book comes out.  In this case, the sales in column 6 for Stepsister and Mermaid are about triple what they had been before.

But what about the goblin series?  Sadly, a new princess book doesn’t do much to bump goblin sales.  Because the goblin books are older and thus not selling as many copies these days, I stretched the graph a little so you could see them there at the bottom.

Looking at the raw numbers, I do see a slight increase in goblin sales in column six.  Maybe five percent?  It’s small enough I’d have to do a lot more work to determine whether there’s any statistical significance, and it’s been way too long since stats class.

So at least in my case, a new book in a new series only moves an extra handful of copies of the old series.

I do think new books help keep bookstores and readers aware of an author, and that readers who enjoy the books are more likely to eventually go back and buy the author’s backlist.  But it’s not an immediate boost like I see for books in the same series.

This has been Jim Geeks Out With Graphs.  Tune in next week when Jim charts hair loss against number of books written, proving once and for all that publishing will make you go bald!


Totally unrelated, a few of you asked for pictures of Jig the runt guppy.  I still couldn’t get the camera to focus, but for some reason it would focus in video mode.  I like this, as the video is actually cuter.  There’s only a brief glimpse of his kinked back about halfway through, and then at the end one of the other guppies comes along to give you a sense of scale.