not mine idea exactly, but like it.
service for not-yet-known book writers. right now the process of publishing your book is very complicated. It is almost impossible to publish your book and get rewards for it. Publishers are like vc, usually say no, since it is risky task to choose what to publish.
So writer will start writing a book. it will publish first 100-150 pages of the book on site. if people will like this book, they will pay fee to author, so he finishes the book. once author collected required money he finishes book. Publishers will get right idea about popularity of the book and author.
Business model is "read 80% free and pay for the last 20% if you want"