Okay, I did the research on this, it isn't quite buy one, get one free, but Polident is offering a ticket if you buy one via the Companion Booking website or calling their 800 number if you send in 5 proofs of purchases. Go to the first link to get the numbers and an idea of how much (and how feasible) it would be to take a trip this way.
For instance, Indianapolis to Orlando would run $320 for the first ticket, $9.95 for the second; plus taxes, security fees, etc. A search via Expedia puts two tickets at over $400.
Hey, I said up front it wasn't buy one, get one free; and I did some of the leg work so you wouldn't have to.