I still haven't received the offers in the mail, but I did receive them via email a couple days ago.
LAST year it was an automatic benefit of 7 Stars that you would get an invitation/offer for NYE, but that isn't the case this year. So, everything would, indeed, be based on ADT (average daily theoretical) and MDV (market daily value).
I saved this image that was sent to me by my host quite a while ago to be able to illustrate this fact when needed. If you look up in the right hand corner you will see $1000+ -- that means this particular offer requires a market daily value of $1000 or more. (Market Daily Value would be all of the Vegas properties combined, in this case.)