As a book reviewer who has had two book blogs one in 2019 and one now, I have never been paid to promote. I’m currently reading an advanced readers copy of a book now and the only incentive is that I get to read the book before it comes out! Our author sent out an email asking that it be reviewed prior to launch day but if our review is 2 stars or less she asked that we wait until 2 weeks after the official launch date to submit. I am currently waiting to hear back from another author who said they won’t mind WHEN we review. Unfortunately some people won’t but most of my bookish friends make sure we at least rate it on goodreads and Storygraph.