Without going into a long story, my ex-wife is a Diamond member that takes frequent trips to Shreveport and about 2 or 3 times a year to Vegas. It may take her about 15 - 20 days to earn Diamond - not great by any means in the HET/CET empire if you will. Her offers are horrible and she only gets casino rates at Paris, PH or Caesar's and she is Diamond.
A couple of years ago she was getting great offers, however her card was still "linked" to my card. When she pulled up or called HET for rooms, she was getting comps because it was "assumed" I would be with her and our cards were linked so she was getting great comp rooms based upon my play and I wasn't even there. I discovered this when we both were going to Vegas over memorial day last year (she was with her new boyfriend and I was going to be with my girlfriend). We both were going to a wedding, etc. and we both happened to book within HET (my at Paris and her at PH) when I found out I couldn't book a room because I was already booked on a comp room at PH. They told me the room was in her name, but my card was used because our cards were linked. At that time I proceeded to work with HET to have her "unlinked" from my card and it became obvious that her okay play was affecting my offers and my great play was allowing her to get free rooms. The thing is she didn't know, nor did I, that this was happening until we both tried to book a trip at the same time.
After she was removed from my account, I noticed my offers improved (another testament to ADT being kind) and her offers plummeted. Where she use to get comp rooms at Paris, PH and Caesar's before, after last memorial day when she booked to Vegas she had to pay casino rates there even though she is Diamond.
ADT is king and while I don't worry about it anymore with HET/CET because I am tired of their lousy VP, I do try to play their "game" right each time I stay there by giving them a solid day for every two days I stay there and the other day I go somewhere else to play full pay vp. Once you kind of learn to take advantage of their system, you can do it an minimize any negative impact on offers. Just don't ever short play at HET if you can help it.
FYI - this may be my last year as diamond with HET as I have been staying everywhere else this year and only stayed at HET for three nights this year. I might squeeze by and retain Diamond another year and it will be interesting to know how my offers later this year and next year are affected as my play at HET slows down over the coming trips I have planned.