I have heard that forum posting can hurt you if the content is not related to your niche. What i'm curious about is if the entire forum is niche related; is that the only way you can get good contextual backlinks? lets say for my niche, carpet cleaning, there are only three forums out there that are for carpet cleaners, however, if home improvement forums were ok in the eyes of google, I would love to start doing some forum posting in those forums. I need to know that it will FOR SURE not hurt my rankings as I have achieved position 1 on google. Thank you gurus!