By the time Dickens began to write Oliver Twist at age 24, he had published his first book, Sketches from Boz, to mild success, and had just finished up the serialized The Pickwick Papers, which had gathered more and more readers as installments continued to appear. The success of The Pickwick Papers allowed him to sell Oliver Twist to Bentley’s Miscellany.
As with The Pickwick Papers, Oliver Twist appeared two or three chapters at a time until the very end, when Dickens’ editors apparently decided that a lengthy (and, to be honest, somewhat tedious) chapter wrapping up various plot threads deserved its own separate publication, as did a considerably more thrilling chapter focused on the final confrontation with a murderer. Bentley’s published one installment per month during 1837-1839, just enough time to allow excited readers to talk and drum up interest (in the 19th century version of Twitter). Dickens then authorized a 1838 book (the 19th century version of DVDs) that let those readers willing to shell out extra money get an early look at the ending (the 19th century versions of pre-screenings and HBO).