[bluGill]

Most books make money from the speaking fees "the guy who wrote the book" makes. I've had a couple classes at work where my company paid $5-20,000 (500-1000 per student depending on how long the class is for) for a guy to come in and give a one week class. As a student in the class I got a copy of the book (someplace on my bookself, I probably opened it a couple times, but never read it). The book is free with class.

I talked to several contractors who said the key to their high value contracts was the book they wrote. Write a book on X and you can make $500/hour doing X at other companies.

Without writing the book you don't get hired to give a class on the book. Without writing a book you don't get to consult on the subject. Once you write a book you are automatically an expert. You still need to sell yourself, the book is part of your marketing materials, but it isn't enough alone to get those high priced gigs.

[ghaff]

It even applies if you work for someone else in my experience. The link isn't so obvious in that case. But I've written several books (both independently and though a publisher) and I'm pretty sure it's been reputationally valuable even though I've made very little money directly.

Writing a book alone isn't enough obviously. But it still sets you apart from others.