The Infinite Monkey Theorem states that a monkey hitting keys at random on a keyboard for an infinite amount of time will type Hamlet (or Romeo and Juliet, or the complete works of Shakespeare, or the Declaration of Independence, or the entire Bible). Variations of the theorem employ an infinite number of monkeys, not just one.
In 2003, a British university tested the literary output of real monkeys. They put a computer keyboard in a monkey enclosure at a zoo. The monkeys produced five pages mostly of the the letter S. One monkey smashed the keyboard with a stone, and others urinated and defecated on it.
What follows is from from http://businessideas.doodig.com/. It's a little bit better than what those monkeys achieved.
The best way to tell how a good idea to publish your book cars look how easy it is for the market. If it is difficult, then sell, not just a good idea.