I wouldnt do it i called the opt out # to get on the donotcall registery and it works for cell phones just as well as home phones, so might not work for all these "Numbers" your generating,besides if you do this your going to get sued big time, not only is it illegal. but it violates The CAN-SPAM Act
unless, like optimus says u allow them to opt out, you have to tell them its advertisement and you have to give them your physical postal address, some of the provisions, but then again even though its illegal won't stop others from doing it. Could always sell it to the chinese.
Good Luck! sounds cool though