That’s not true. I wrote the Panther book, Advanced Perl Programming, and easily made way more than 100k. Of the 25-30 or so dollars the books cost, I got 10% per copy, or $2 after taxes. The first print run of 35000 sold within the first three weeks.

The Camel book was already a huge bestseller, and was one of the anchor books of the early OReilly series. It made Larry a pretty penny

The 4th edition authors included brian d foy, who said "I think Tom [Christiansen] and I worked for about two years to produce the current edition. I certainly wouldn't want to spend that much time again to make less than $1,000... It's a huge effort from the editors and proofreaders and the book won't sell enough to make back the effort they put into it." https://www.reddit.com/r/perl/comments/1ns5r9n/comment/ngmvt...