title_body: What was the average income from ebooks for independent authors in 2013? Ebooks have been a boon to independent authors, providing a path to audiences, unmatched in the history of publishing.  The field is rather new, and currently there is not even Wikipedia page Independent author. 
  
  If possible what is the number of Independent authors who published English language works in 2013, and what was the average incoming from those 2013 works?
upvoted_answer: Statista (The Statistics Portal) looks like it has some relevant ebooks revenue information (though not exactly what you are looking for). Unfortunately, you are forced to sign up for a premium account to access most of the reports. A sample report that they actually show you some of the information for is here (Global e-book revenue from 2009 to 2016*, by region (in million U.S. dollars), obviously some is projection).
  
  I did manage to find an informal survey done by Marie Force about independent publishers here (covers total unit sales broken down between 2010, 2011, 2012 and some of 2013) . Here is an excerpt:
  
  
    The conversation on the loop led to me post an informal survey to get
    an idea of how our members and their self-publishing friends are
    really doing. I didn't ask people to give dollar amounts, but rather
    just their number of sales in 2010, 2011, 2012 and so far in 2013. I
    asked them to list their most successful book in 2012 and how many
    copies it sold. At the outset, I want to say that this survey was
    informal. There is nothing scientific about it, but it does provide an
    interesting snapshot of how self-published authors are really doing.
    
    To give context to the numbers, I wanted to also provide a guide to
    what the most popular price points translate to in actual dollars.
    Using Amazon's conversion chart, here it is:
    
    0.99 (35 percent royalty): $0.35 per sale
    1.99 (35 percent royalty): $0.70 per sale
    2.99 (70 percent royalty): $2.04 per sale
    3.99 (70 percent royalty): $2.74 per sale
    4.99 (70 percent royalty): $3.44 per sale
    
    While I didn't ask authors to list their most common price point
    (which I will add to the survey next time), I thought the breakdown
    above would be enlightening to the authors out there who might be
    waffling about whether they ought to try their hand at
    self-publishing. If you are thinking about whether or not you should
    dip your toe into the revolutionary waters, ask yourself these
    questions: When was the last time I made $3.44 on the sale of one
    book? When was the last time I made even $2.04 on the sale of one
    book?
  
  
  She then goes on to post a bunch of survey results broken down by author. Here is a sample of one of the survey results:
  
  
    Elisabeth Naughton Romantic Suspense and Paranormal Total number of
    self-published titles: 12 Total number of self-published sales in
    2010: 0 Total number of self-published sales in 2011: 0 Total number
    of self-published sales in 2012: 102,179 Total number of
    self-published sales so far in 2013: Jan-March 2013: 370,059 Most
    successful book in 2012 and how many sold: MARKED - 30,673 copies
    
    I've been traditionally published for four years and my income comes
    primarily from my self-published titles, NOT my traditionally
    published titles.