If you look at total unit sales of books, both print and electronic, of the top 9 categories where e-books scored a significant percentage of sales, 8 were fiction. The percentages were: Science Fiction 19%, Christian Fiction 16%, General Romance and Mystery/Detective both 14%, General Fiction 12%, Espionage/Thriller and Juvenile Fiction both 9%, and Young Adult 8%. However, the non-fiction category, Literary/Classic, did nab the top spot with 20% of total book sales, but this is mostly because many works of literature that are not covered by copyright anymore are being sold electronically.
So there you have it, time to write some fiction?