Digital publishing site Smashwords has published more than 138,070 books, exceeding a total of five billion words.

Smashwords founder Mark Coker revealed some interesting statistics in a blog post: “As I write this, five of the Apple’s iBookstore’s top 20 bestsellers are from Smashwords authors R.L. Mathewson (read our interview with R.L. Mathewson here), S.C. Stephens (we’ll publish an interview with S.C. very soon at the Smashwords blog) and Jamie McGuire (Jamie just sold rights to a traditional publisher).  That’s one in four.  12 months ago, those five slots were occupied by the books from traditional publishers. 12 months from now, how many more slots will be occupied by an indie author?  That’s up to you.”

AppNewser has more about sales projections: “According to Coker, Smashwords retailers will sell $18 to $20 million worth of eBooks this year.”