The Terms of Service does not forbid offering your product at a discount as part of a launch promotion. Amazon has not taken disciplinary action against any sellers who utilize product launches in their marketing strategies. Giveaway coupons are common in the Amazon seller community for special deals like any retail store. Amazon may take issue with your listing if you are running coupon codes indefinitely as a means to subvert competition. Additionally, Amazon will take issue with any fraudulent or misleading claims or activity from you or your ads; as long as you are transparent and offer a real product, there should be no problem using a product launch strategy.