If you want new customers/clients/patients offering a discount will usually bring them in!  If they were referred or thinking of calling/using your business, knowing they will not have to pay full price to 'try' you out will get them to the phone or your door!  If you are established but want to showcase a new product, service or opportunity, then general marketing 'with a punch' works fine; however again, if you offer a discount with it - maybe to the first 25/50 callers -  Bingo!  You are In!!! :)