Long time ago, travel writers got "freebies" then wrote about the place/cruise/hotel etc.. ... the better writers -in general - were objective ... others wrote puff pieces. Now a day reputable magazines and publishers insist writers be able to prove they paid their own way.

In my newspaper days, Ottaway Newspapers/Dow Jones required that the company pay any charges associated with the subject of a story (i.e. theater tickets for a play) to avoid even the appearance of impropriety.

I can't see untried writers benefitting from payment-for-book ... just the well known. And do they need to do it?

I have no objection to names of products in books when they flow naturally in the narrative. But "Paid Placement?"

Too bad we can't hear an opinion on the subject from Truman Capote !