One helpful thing to know about shills (people who post rave reviews under alias for their own operations, or those of family or friends) is that they have no restraint. In fact, lack of restraint is an inherent part of what makes a shill a shill! Take a look at this page listing a few Trip Advisor reviews I wrote (anonymously) about hotels I stayed in during my massive Chow Tour.
Notice anything strange? Users generally find me quite a helpful reviewer. On three of the four places I reviewed, all raters rated my review "helpful". On the fourth review, I was found remarkably unhelpful, and by a much larger pool of review-raters. Take a look, and you'll see I'd written a tepid review for a very highly rated hotel; a review in stark contrast to the many raves for the place. And you'll see a number of others whose experience failed to live up to those of other reviewers. They were voted "unhelpful" as well, and by a larger-than-usual pool (relatively few Trip Advisor users rate reviews...much fewer than on, say, Amazon).
In things like food, books, movies, etc., avid-but-honest partisans will annoyingly down-rate a review's helpfulness simply because they disagree with the opinion. The most thoughtful negative review of Star Wars, for example, will swiftly be marked "unhelpful" by scads of incensed fanboys. But while the Montreal Springhill Suites may have its genuine fans, they are unlikely (unless they're stark raving bonkers) to be quite so fervid. No one, in other words, but an insider would down-rate a well-written negative review of a hotel. But, again: lacking restraint, insiders can't help themselves.
So the upshot is this: if a venue on Trip Advisor seems over-hyped, watch for down-rated "helpfulness" ratings on reasonably thoughtful negative reviews. If so, you should be extremely skeptical of ratings for the venue.
It must be noted, however, that some good - even great - businesses shill. So some raves for shilly places may be legitimate. Of course, it's hard to distinguish, and that ambiguity greatly reduces the power of legitimate raves. What a pity to see good businesses devalue genuine consumer word-of-mouth via their own underhandedness!
The penalty for dishonesty is always devaluation of one sort or another. Quality operators would do far better to let their reputation grow organically! They also have a vested interest in seeing earnest consumer opinion networks retain credibility, because a robustly authentic consumer network is the best imaginable friend to quality businesses.
Lousy operators who shill would be better served in spending their time and energy* improving quality, rather than striving to guerilla market mediocrity. Customers lured to a poor experience via subterfuge are likely to become unhappy customers, and unhappy customers can be more expensive, in the end, than no customers at all.
*In some cases, they spend hard cash. Public relations firms have over the past couple of years begun offering outsourced shill services. We at Chowhound were aware of this early on (one perq of running a beloved resource is that we have moles pretty much everwhere), and the Wall Street Journal reported on it late last year.