I’ve been carrying the May 14, 2011, Billboard magazine around with me since one of my Journals colleagues put it in my mailbox. I’m convinced that it somehow tells the future of book publishing.

Ed Christman’s Retail Track column includes a table of the “Top 20 U.S. Music Accounts.” iTunes was number #1 in 2010 with a 32.98% market share!  I remember the early days of the service when all of the reporting about iTunes claimed it wouldn’t earn much money but was necessary to provide easy content for all of those iPods.  At least that’s the way I remember it.

Now, somehow, iTunes has a 33% (and growing) share, followed by Wal Mart (10.66%), Best Buy (8.68%), Target (7.79%) and Amazon (6.88%).  The first actual “music store” is Trans World (Sam Goody, f.y.e.), which comes in #7 at 3.47%.  Wireless carriers Verizon, Sprint Nextel, T-Mobile, and AT&T appear at #8, #15, #18 , and #20 respectively.

OK, what’s the publishing connection? The Billboard chart makes obvious the importance of the current e-reader battle between Amazon’s Kindle and B&N’s Nook.  Win the e-reader market and a large portion of the e-book market will likely follow.

This post from the Ask the Agent blog references Bowker’s retail numbers for 2010. Barnes & Noble is #1 at 23% followed by Amazon.com (15.1%), Borders (13.1%), Wal-Mart (5.8%), and Warehouse Clubs (4.0%).

I wonder, in five years will there be a clear e-reader winner and what will the Top 20 U.S. Book Accounts look like?