According to R.R. Bowker, the company that issues and maintains information about ISBN numbers, there is a grand total of more than 1,879,000 books available to the world. About 78 percent of the books that have been published came from small publishers, according to the Publisher's Marketing Association (now the Independent Book Publishers Association).
Many people want to know how many books are published annually. According to R.R. Bowker, there are about 175,000 books published each year. That is an average of 479 books each day, or about 19 books every hour. According to this statistic, by the time you finish reading this, another book will probably be published somewhere!
According to Publishers Weekly, there are more than 86,300 publishing companies worldwide. Self-publishers make up the vast majority. In fact, self-publishers make up about 86,000 of that figure. There are about three or four hundred mid-sized publishers and six large publishers that are well-known. These figures give you a good idea of how difficult it can be to have a book accepted by a major publisher.
Book industry professionals usually gauge total book sales based on Nielsen BookScan data and reports from retailers, distributors and wholesalers. But book sales are largely under-reported. For one, many small publishers sell using nontraditional methods. Instead of selling in stores, they might sell hand to hand at street fairs and on their Websites. These sales are not reported to Nielsen's BookScan service. In fact, BookScan even admits that it is only tracking about 70 percent of total book sales but industry professional still look to it as the gauge for book sales. So while book experts estimate that 3.1 billion books were sold in the United States (latest stats from the Book Industry Group), considering the number of self-publishers on the market, it's very likely that that there are many more.
If there is one thing that publishing professionals can agree on, it is the fact that book publishing statistics are sometimes obscure, and can sometimes be either fudged or understated. If you have seen the New York Times Best Seller list, you probably notice that the paper never really report how many books those titles actually sold. That is because it is hard to estimate. Publishing facts are largely based on the assertions of large publishing companies (which are at times exaggerated) and stats from industry-tracking firms.