TripAdvisor "doubles" conversion rates???

I ran across an article on Hotelmarketing.com that made me want to put TripAdvisor or other user generated review onto my millenniumhotels.com site.

Just kidding. But it was an interesting read nonetheless.

"Online shoppers who look at TripAdvisor reviews on the Hayes & Jarvis site book trips at double the rate of online shoppers who have not seen the TripAdvisor reviews. Hayes & Jarvis is the first tour operator to provide customers with reviews from TripAdvisor."

Details:

"All visitors to the hotel description pages see TripAdvisor ratings (one to five “owls” depending on user popularity) and 20% of them click on the “Read Reviews” button. Over the four months since launch, the visitors who read the reviews converted at twice the rate of those that didn’t."

Obviously I wouldn't put Tripadvisor on my own site, but this data is certainly compelling. However - this being the web - there are a number of questions that need to be addressed before we can trust these numbers:

1) People surf and search across sites all the time when they do research. For their site, people who start looking at user reviews are possibly further along in their buying cycle than those who have not looked at user reviews. So since they are more ready to purchase, the conversion rate would be higher. So how do we know if the conversion is higher because they are ready to purchase or because of the user reviews?

2) On average, people visit sites more than twice before they purchase and for OTAs this is even higher. So if a person visited 3 times before she purchased, the scenario could easily be that she was researching the first 2 times, and the 3rd time she is ready to buy. She checks the user reviews and then buys. This would give the user review visit twice the conversion rate.

3) On the same vein, are we talking Daily Unique Visitors, Weekly Unique Visitors, Monthly Unique Visitors, Lifetime Unique Visitors or are we just talk Visits? The data would be very compelling if these were Lifetime Unique Visitors rather than non-unique Visitors from each Visit.

In any case - if nothing else - for Hayes & Jarvis, the reviews will serve to make the site more "sticky" and also provide additional features that improve usability and relevancy.

So is there anything similar we can do for a hotel group? Something that would be non-destructive, easy to maintain, and trustworthy (from the consumers' POV).