You could just ask me, if you wonder something like that.
The answer is that no, I don't directly profit from Ancillary sales, although I have had the two largest ancillary companies on the internet as clients at one time or another, and they both either sell my book directly on their site through an affiliate program, or through sites they own.
So...they both help sell my book, and I've worked for both. But if they sell X products I don't get Y money. If they didn't make any money, they couldn't hire me...but I don't get any % of anything they make as a result of ancillary sales.
I do research and writing for them, and get paid for that alone. I make zero money off sales of ancillaries.
In fact, my first ever article (Title: "Ancillaries" and later rewritten as "ABC's of Anti-E's") when I was writing under the screen name "hooker" was written totally for free by me for the board I was admin on at the time. I got no money or free products at all for it, and never asked for any. I just wanted to write the piece.