I opened my email the other day, and was surprised to find a letter from one of the book tours that I work with. The letter told of the new changes and requirements that they are implementing... A tour host is REQUIRED to give a GOOD review or they are not allowed to post, but are required to contact them instead and they will work with the reviewer to come up with a reasonable solution/review.
Another tour that I had worked with in the past not only required good reviews, but if you couldn't post a good review, you were required to leave that tour and send the book on (at your expense!) to another person that agreed they would post a glowing review.
The reasons that are given for this requirement is that these groups/individuals that arrange the tours are paid to promote the books and the authors want (some even demand!) good feedback on those tours. Does this mean that when you visit a site that is hosting a tour, you can no longer trust the review that's posted? Sadly - it is possible. It seems like this may be the route that more are going.
Personally, I was livid when I read the new requirements. I don't get a cent for doing reviews and working with tours. Yes, I get a book, but if you consider how much time it takes to schedule things, read the book, post the review, and run a giveaway, it would be so much easier and economical to buy the book outright. In fact, some tours I've worked with supply the books from NetGalley, so they expired - like a library book.
I try to pick my books wisely - books that I would enjoy reading. I don't post many reviews stating that the book wasn't worth my time. Usually I like the book, and my reviews state that, however, don't ever REQUIRE me to post a good review. I didn't monetize my blog for a reason - so I don't feel obligated to post a good review for anything. I am honest about how I feel about a book and no one is going to tell me how post. I post because I'm a book lover and want to share my experiences with other book lovers. I will not be bullied to post a good review!