In the afterword of its novel Fahrenheit 451, Ray Bradbury states that
I didn't know it, but I was literally writing a dime novel.
However dime novel seems to have a negative connotation, according to the following definitions:
a cheap melodramatic or sensational novel, usually in paperback and selling for ten cents, especially such an adventure novel popular c1850 to c1920.
http://www.dictionary.com/browse/dime-novel
Dime novel, a type of inexpensive, usually paperback, melodramatic novel of adventure popular in the United States roughly between 1860 and 1915
On this site, dime novel is used as an answer for the opposite of a gripping book.
The question is, if dime novel has such a bad connotation, why does Bradbury use that term to refer to one of its most acclaimed work?