According to a recent Mashable article, American publishers, for the first time, are earning more dough from eBooks than from hardcover book sales.
So how much are eBooks bringing in? If you don't include children's books-- $282.3 million in Q1 (a 28.4% increase from Q1 in 2011).
Children's and YA eBook sales grew 233%. That's $64.3 million!
Paperback books are still the big earners ($299.8 million for Q1), but that seems to be declining as more and more Americans purchase eReaders, tablets, and smartphones.