And in the case of chess books, an advertorial is quite different from a good review. I very much enjoy reading a good review on a chess book, with all the good things and bad things. With an advertorial the language is quite different and it is very hard to get informed well about what you really get when you buy the book. With honest critique, I very much enjoy reading about the bad parts, and if they are not bad for me, or just a nuance, it might be a really good book for me. Only an honest review can give me that.

So no, an advertorial for a book does not do anything for me.

Chess books, maybe. Chess sets? I'm sure most people playing chess on lichess are aware of chess sets and could get a hold of one without an ad.