The comments here are incredibly harsh. As someone who has self published two books, quite a lot of this resonates with me.

First book addressed a timely topic but ultimately aged out very quickly and I got burnt out trying to keep up with updates. It made roughly $80,000 in lifetime sales, of which I kept 96% (credit card fees + hosting overhead).

Second book addressed a broader niche but fell into several of the traps he describes and only made $3000.

I will likely buy his book and try to apply it on either a revision of book two or something new.