The market for authors is actually extremely dismal. Most authors sell almost no copies. A large portion of authors not only make no money but lose money. The averages simply reflect the sales of the very few bestsellers divided by all the many books published which mostly sell almost nothing.
In the rest of this topic, I will simply list some of the statistics for easy reference.
If anyone else has statistics, please list them to. Please include your source, though, as that is the point of this topic.
half [of DIY authors] made less than $500
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with less than 10% of self-publishing authors earning about 75% of the reported revenue and half of writers earning less than $500.
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Half the respondents failed to reach $500 in royalties in 2011, and a quarter of the books are unlikely to cover the direct costs of production.
theguardian.com/books/2012/may/24/self-published-author-earnings
According to Jenkins Group, a premier publishing firm, 70% of books don’t make a profit. When people joke about the cover designer making more than the author, it’s often the case.
incomediary.com/7-things-learned-publishing-book
The number of new self-published titles in the USA alone rose from 32,000 in 2006 to 135,000 in 2007 and over 300,000 in 2009, but the average sale was 10 copies. In 2010, 2.5 million ISBNs (new book identifying numbers) were issued. In a recent interview (2015) with the founder of MyBestseller, he quotes 95% of books as selling less than 100 copies.
johnhuntpublishing.com/index.php?id=66&i=0&a=81
a survey reveals that 54% of traditionally-published authors and almost 80% of go-it-alone writers are making less than $1,000 (£600) a year
theguardian.com/books/2014/jan/17/writers-earn-less-than-600-a-year
90% of self-published authors sell less than 50 copies of their book in their lifetime
pieceofcakepr.com/why-90-of-authors-sell-less-than-50-copies-of-their-book/
The majority of authors make less than $1,000 a year, according to a new report from Digital Book World. Almost 80% of self-published authors and more than half of traditionally published authors earn less than $1,000 a year [...]
The research revealed that only 10 percent of traditionally published authors made more than $20,000 a year and 5 percent of self-published authors made more than $20,000 a year.
adweek.com/galleycat/most-authors-make-less-than-1000-a-year-dbw/82866