I just had an interesting experience booking an offer at CP next week. While trying to book Caesars Palace on a particular day, the offer was available online thru the total rewards site and rate calendar, but the site would not let me book and gave me an odd error. A call to the TR reservations line, told me the offer code I wanted to use was oversold. I then used essentially the same offer offer, with a different code that expired 30 days later (Example 4/30 - 8/31 instead of 7/31) just with a Saturday arrival. Guessing some heavy convention traffic is blocking 5/30 arrival. Anyway, it seems CET is tightening up the number of a particular offer code for free nights they will allow to book. I am guessing to ensure a good mix of paid vs comp nights. Now on the flip side, I have been low playing them as of late so my ADT has been on the decline. So I wonder if they are enforcing additional rules as well, even on Diamond level TR members. Historically I have see in these cases nights not eligible, offered as "Free" on online booking versus "COMP" via the TR offer.