Some E-Book Sales Statistics

So, I was putting together some figures the other day for tallying up a "total e-book sales" number (because it was being asked for). And as I'm big on stats as it is, I decided I'd post a few. Since we've only been through three full months this year, I'm ignoring my 2014 sales.

Heroes Die Young was released in 2008.

Friends in Deed and Seeker were both released in 2010.
Dead or Alive, The Cure, and my first Triple-Shot (Dead Man's Forge) were all released in 2011.
Death Brings Victory and my second Triple-Shot (Temptation) were released in 2012.
My third Triple-Shot (Downtrodden) was released in 2013.

Total sales across all of my titles (again, only through 2013) is 645 since Heroes Die Young was released. A rather piddly sum, I know, but that's life. All of that in mind, I've had the following sales per title per year (for convenience, I've also included total sales per year.

	HDY	FID	DBV	DOA
2008	95
2009	33
2010	9	28
2011	27	15		13
2012	50	22	35	47
2013	14	5	13	2

	DMF	TEMPT	DT	Seeker	Cure
2008
2009
2010				10
2011	6			38	15
2012	22	8		27	42
2013	16	15	10	13	15

	Total
2008	95
2009	33
2010	47
2011	114
2012	253
2013	103

So, I hesitate to start making conclusions based on these stats, since it's been proven over and over that sometimes blind luck can cause sales. And looking through the numbers, there doesn't seem to be any rhyme or reason to sales leading to more sales (of later books in the series, etc.). However, even with all of that in mind, at least one thing seems to stick out.

Generating new material for publication can generally help sales. I had three releases in 2011, and saw a marked increase. I followed that up with two more releases in 2012. With those five new titles, my sales in 2012 were five times higher than in 2010. Granted, in  2013, I had no major releases (other than the third Triple-Shot), so my sales dropped off last year. So, not only is it necessary to continue to produce new material, but it's also important to continue to do so on a regular pace. This is something I struggle with, myself, and need to work on. Hopefully this can help motivate me...