This showed up in my Inbox a month ago. Has anyone booked this? The "Fly to Vegas on Us" part is a voucher for your next flight, not the current one, hence you need to take two trips to realize the savings. I was curious to see if that voucher comes with more "hidden" restrictions, like limited airlines, blackout dates, etc.
https://www.harrahs.com/MakeReservation.do?propCode=ILV&packageCode=IIAF2
https://www.harrahs.com/MakeReservation.do?propCode=ILV&packageCode=IIAF2