New indie authors sometimes make the mistake of going onto the Amazon forums and pretending they're someone else-- or possibly having one of their friends promote for them. In either case, if you post a glowing five-star review for a book, and then post the exact same verbiage to thread after thread, while claiming you never heard of the author before now, NO ONE is going to believe you. It's blatantly obvious that you're either the author, or a friend or family member. It's especially blatant when the poster in question has posted absolutely no reviews except for this one book. (Edit: And when I can do a search on you and find that you promoted the paper edition back in 2009 and referred to it as your own novel, that's even more blatant. Old threads never die!)
So a word of advice to newbies: Don't spam the threads as yourself, but don't think you can avoid the appearance of spamming by pretending to be a disinterested reader, either. Disinterested readers don't post the same promo on five or six threads in the course of an hour. Readers aren't stupid, and this kind of thing makes ALL indie authors look bad. Just stick to the promo threads and post to them a couple at a time. If your book is good, people will find you, and you won't run the risk of ticking readers off.