Every year I update my industry book sales page that combines the financial statements of the Big Three (Barnes and Noble, Borders and Amazon) with some government and trade statistics to give a thumbnail picture of retail book sales. An interesting facet of the book industry is that the only numbers anybody really trusts are from a third party, Nielson, who simply counts books at the point of sale. None of the industry organizations are sufficiently comprehensive in membership to produce trustworthy numbers through internal surveys, and some may have an ingrained prejudice against bean counting.
There's no particular reason for self publishers to fixate on the size of the book market, which is in the low tens of billions of dollars, because the most successful of us isn't even a blip on the radar in that context. It would be interesting to know if all of us added up together amount to something on the order of a major trade, or if our sum total doesn't come to a hill of beans. Unfortunately, I don't have any ideas for a methodology to determine this, even if I had the resources.
One interesting measure would be to learn how many individuals earn their primary income through self publishing, and then to compare that number to the number of employees at a large trade. I don't think it's possible to extract that information from the IRS statistics (I've tried), and a survey by way of the Internet would be as self selecting as anything attempted by a small publishers organization. It's easy for me to say that I know a dozen or so individuals who earn a living self publishing, but maybe that's everybody!
OK, that would be an exaggeration, but I can't help wondering how many self publishing authors have figured out the industry to the extent that they turn down offers from the big trades on a regular basis. What got me thinking about it was a recent correspondence with an ex-editor of mine from a big trade in which I mentioned that self publishing authors aren't likely to put them out of business any time soon. I'm not really sure why that's the case, except that most authors, even veterans with a firm understanding of the book trade, would rather work for royalties and advances than on spec.
Most work-a-day nonfiction authors could afford to at least experiment with judicious self publishing, but the big trades hold the lure of bestsellers with a largely illusory marketing advantage, and a book contract with an advance is a bird in the hand. It might be an honest recognition on the part of many authors that they just don't want to be in business for themselves with all that entails, including a slow ramp-up time. Still, it seems to me that the best time to launch a new business is when you're already earning a living in a related field, as in working as a trade author. If you wait until you need the money, it's probably going to be too late to figure it out the business in time to pay your bills and remain independent.