Yes, it's changed a lot since I started publishing in 2008. Back then you couldn't review any book that you'd published, even if you weren't the author. That used to really annoy me because if a publisher can't support their authors, then who can? But now, whenever I buy a book, even if it's my own, they send me an offer to review. Of course i don't review my own book, but maybe I should tell my winners of giveaways to send their reviews to me, and I will post them on Amazon seeing as I bought the books in the first place. I've already told them to post on Goodreads, Waterstones, Google, etc as these have no such restrictions that I know of. Shame I'm terrible at writing reviews anyway.