I am happy to submit my opinion and my own experience both as a buyer and a seller.
Though it may sound obvious, the INFORMATION you plan to cover MUST BE WANTED (Dare I say coveted!) or there is really no point in spending the time, talent and treasure in the first place only find that no-one WANTS the information you are offering.
This valuable insights is waaaaaaaaaaaay too often NOT given its due! There are tomes and volumes of unwanted books floating around the universe for sure, PLEASE dont let that happen to you!
This is where market research, a marketing PLAN and a full due diligences is necessary! Certainly if you target audience is niche, (and small at the same time) you will want to KNOW THAT up-front as it will determine how you plan to publish including the format.
This is not a marketing and publishing your book lesson, so I will move on. I hope that first part makes sense to you.
MAKE SURE you have enough already SOLD (or well committed to!) before ink hits paper, unless you have more money and a lot less sense than The Donald himself! (See Point ONE!)
I am sort of an odd reader, and since you asked for opinions, What I look for is a book is something I REALLY (Even desperately) want to know usually to help me grow in some way!
Offer me (for me and my reading preferences) information that will help me to become a better person, performer, business owner, professional, husband, leader, community advocate, manger/steward of resources, listener, dispenser of wisdom, skill sets improved, mentor, mentee, student, teacher, friend etc. and I am YOURS as a buyer and reader! I have literally spent millions on my personal education and development, and I will continue to do so I am a junkie of sorts.
again, that is just me.
Thinking of YOU and Your Success!
I am at your service and In HIS Service,
Deano (loves to learn and share) in Reno
I dont much care how fancy or slick it is its the INFORMATION I want! (TIP) And I will pay Good money for great information!