Why do people hire ghost writers?
1. Inadequate writing skills - some people have so many brilliant ideas inside their heads, but they don't know how to organize them and put ink to paper. Oftentimes, it cost them more to hire an editor to edit their manuscripts, so they choose to hire a ghost writer from the beginning.
2. Not enough patience - writing a book isn't a walk in the park. It takes time and a lot of patience to create a coherent one. Some people have great ideas, but are just not patient enough to sit down night after night to write.
3. Time - which brings us to the element of time. Since writing takes time, some people just can't afford to spend time writing a book. They would rather work on their businesses or just rest than to spend 30 hours a week putting their ideas to paper.
4. Sellable outcome - intelligent business people know that writing a crappy book or ebook isn't enough to sell it. So they hire someone better than them to tell their stories. In the end, they get more benefits.
What do you think are other reasons why people hire ghost writers aside from those mentioned above?
Do you think you would like to hire a ghost writer for your book idea?
Type your answers in the comments section. 
