Novels, available in paperbacks now, are readily available to people, and cost is no longer a factor in their consumption. Drama, on the other hand, has to be experienced in person to understand the playwright's real intentions. Novels can attain a level of epic sweep and complexity of plot that poetry and drama stuggle to sustain due to the conventions of length. They also can be more straightforward in language, as opposed to poetry, which many people find difficult to access. Popular novelists have proven very successful at marketing their works to large audiences, often in spite of the rejection of critics. The novel has also proven very adaptable, as the new genre of graphic novels shows. Novels also lend themselves to film adaptations (as does drama) which increases their popularity. The novel has become the focus of the publishing industry, far more than drama and poetry.
keeping in view the historical literary development, these three genres poetry, drama and novel have eveolved one after the other. Initially it was poetry and drama and then novel but novel grew out to be a more effective genre because of certain factors. Unlike poetry the ideas are more eloborately depicted moreover unlike play/ drama it needs not to have certain characters on the stage to be acting.
Novels with the passage of time grew to be more popular and successful because the readers during and after industrial revolution had less time for the lengthy episode dramas which were in vogue earlier in renaissance period/ shakespearean era. Novels have in their possession the ability to move the readers in to realm of the writer's world. They experience the sorrows, sadness, tragedies, happiness, ecstasy, joy, humour, cynicism, infact, every feeling emotion and sentimental note being portrayed by the characters of the novel. The success of novels is that a reader in his little room is able to move all around the world where ever the writer may take him, all he requires is the copy of the novel that he likes, or wishes to go through.
Either it was any Romantic writer like Daniel Dafoe, Jonathan Swift, Henry Fielding, Jane Austen or present day bestseller novelist J.K.Rowling, every writer makes the readers move into a different world and the perception of every reader differs equally. Through which they come across their own personal catharsis, something that was earlier related to drama only.
This is the reason that even the most expensive movie versions of the novels are not as apprecited as the cheap paperback novels are.