If you are about to post a recommendation for an author or book, please read this first:
If the author is you, consider: ordinary civility demands that before making a purely self-serving post, one needs to have established something of a right to such a post, which right is acquired by building a history of meaningful contributory posts to the forum. (And that is by no means some strange policy unique to the forums on this site.) It is quite rude to enroll on a forum for the sole purpose of touting your goods. If we have come to know you by your posts about books, we will be well enough pleased to find that you are now become an author yourself; but till then, just popping the door, shouting your "buy me!", and dashing off again while the door slams will not earn you friends (or readers), nor will your post survive long (only till I see it).
If you are not the author--or a friend acting on his or her behalf--you are still not excused from basic civility. A person established as a regular contributor to a forum will generally be cut some slack--how much varies from forum to forum, and here I'm fairly easy-going--when it comes to announcing some new product he or she has discovered. But "drive-by postings", as David Tate has so pungently described such things, are so obviously wrong that one wouldn't think it needs comment.
None of that is to discourage new members here from starting out with an author recommendation: that is not the point. Everyone has to start somewhere. It's just that the "price" expected of you for such a post is some meaningful comment on why you are so enthusiastic about the matter. Such encomia as "Wow, I really loved it, this is the best book I've read this month / this year / in my life, the author is really great, it's really wonderful" are basically requests to have your post deleted. No one expects New York Times Book Review standards, but we do expect that if you like it so much, you can and will be able to explain what the book is about (more or less)--which does not require spoilers--and in what ways the author has impressed you in telling the tale (or tales).
At bottom, I think that most of the explanation above is needless. Civilized folk know when they are behaving reasonably and when they are not.