Jason Boog on GalleyCat reports that digital books are now “the dominant single format” in the adult fiction category, according to a new BookStats report from the Association of American Publishers.

eBook sales exploded in the adult fiction category last year, accounting for 30 percent of net publisher sales in 2011–up from 13 percent the year before.

At the same time, net sales revenue from eBooks increased from from $869 million in 2010 to $2.074 billion in 2011. That’s 15 percent of net revenues for publishers. AppNewser has more about how these numbers have affected the total US book market.

Here’s more about those eye-popping figures, from the report: “Adult Fiction eBooks revenue for 2011 was $1.27 billion, growing by 117% from $585 million in 2010. This translated to 203 million units, up 238% from 85 million in 2010.”