The truth is that having written a great story or the deepest poetry is not enough if you want to launch a book, printed or digital, that seeks to compete and be successful in this multi-million dollar market. 

For your work to have a hole in said competition,
has to meet a number of requirements ranging from professional editing to creating excellent
and attractive cover, an adequate advertising campaign and even constant management and monitoring of sales and the positioning of the work in relation to its competition.