Why are you writing you book? Do your core values match these:
Explaining how you function to your specific target audience
Most companies make the mistake of thinking that their customers either know how their business works, or that the process is too complex for them to understand. In both cases, the stronger the reason to explain to your audience how your business runs and why you are different. It would be pleasing to hear that clients are interested in knowing and if explained well, it could quickly become your USP as many competitors don’t do this. Be the first. A book is an excellent way of sharing information.
Example: If you are a dental cosmetic surgeon who is looking at increasing sales of a particular procedure, and there is cut-throat competition, it might even be a good idea to write a small 75- page book and self publish it for free distribution among potential prospects.
People like to have precise information, and will not mind paying for knowledge, more so if they percieve you to be an expert in your field. It would however not be a great idea to publish such a book using a traditional approach and sell your book in bookstores since your target audience is too selective. Imagine running an advertisment in a paper and offering a free book on the procedure. A lot of people might call for it, and would also create a higher closing ratio.
Making more profits on book sales, but you have your audience to sell to
This is a good idea for motivational speakers or people who generally address an audience and quite often a book makes a great product to sell. But it is only for those who know how to sell it. The advantage over traditional publishing is that here you have all the profit, only incurring a nominal printing and logistics fee.
In a nutshell, I would recommend self-publishing only if you have a very specific audience to target and you are sure you know how to do it.