For what it is worth, I am working with TA on an issue of 18 positive posts appearing on the same 2 days, following an e-mail by the hotel owners to past guests. I reported it to TA, and hope they will yank the hotel and the reviews. It is not a luxury hotel, but still, it emphasizes the need to be careful with TA ratings and reviews.

"Hi everyone,

...We just had a couple who stayed at our hotel give us a bad review...
If you would be so kind as to write some nice reviews at
http://tripadvisor. com to "bury" their bad review, this way nice
people looking at tripadvisor will know that we are a nice place.

You just type http://tripadvisor. com and then type in [hotel name].

I appreciate it everyone."