From Digital Book World:
Below is a list of publishers who have made the Digital Book World Ebook Best-Seller list in 2013, ranking them by number of appearances.
While Hachette made a very strong showing in the first half of the year, leading all publishers in ebook best-sellers, Penguin Random House had almost as many best-sellers in the second half of the year (230) as Hachette had all year. If you add up PRH’s numbers with Penguin’s and Random House’s from the first half of the year, the company had an astounding 478 ebook best-sellers, about 40% of all the best-sellers from 2013.
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The other big story in the best-seller rankings in 2013 was the strong showing of self-publishing. Aside from Hachette and Penguin Random House, self-published authors (when viewed as one single publisher) had more best-sellers than any other single publishing house.
Link to the rest at Digital Book World