I agree that writing a book is likely not worth it for you.

But, it's somewhat more lucrative than you describe. Self-publishing has opened the doors to much higher royalties, and the stigma has vanished.

I self-published with Createspace, amazon's publishing arm. I get 43% of revenue (not profits) as a royalty. Printing costs are covered from amazon's portion. If I had a Kindle version, I would keep 70%.

Here's what the book looks like: http://www.amazon.com/Hacking-LSAT-Explanations-Official-Dia...

I am comfortable posting here as I expect exactly zero people on HN would need to buy it, it's pretty niche.

Design + proofing costs were around $500. Reviews were easy to get from advance readers.

I've found a tangible benefit from being able to show this page to people in my industry. The learning curve to produce it wasn't very high.

Anyone with a pre-existing following shouldn't have trouble marketing a book. It may be worth many people's time to write one book both as a passive income project and as a credibility indicator. The royalties are great if you get any kind of volume.

A book. I'm an LSAT instructor. Originally these were sold through an affiliate (still are) and this year I published it.

http://www.amazon.com/Hacking-LSAT-Explanations-Official-Dia...

I also built up a local LSAT tutoring business.