So you need to book a hotel in another city. If you’re like most people, you look the property up online and read reviews written — ostensibly — by other regular folks just like you who have stayed there.

That scenario happens millions of times a day, but should we really trust the information that’s posted on a website?

Like everything else on the Internet, travel reviews should be consumed with a healthy dose of skepticism. Travel review sites like Tripadvisor have become increasingly popular in recent years, though Tripadvisor’s reputation has been tarnished by allegations of hotel and restaurant staffs filing fake reviews to boost ratings.

Then there is the question of who are the reviewers. I addressed this with a Zagat review of cruise lines last November. A patently bogus survey was produced by Zagat — yeah, the people who review restaurants — for the cruise industry, rating cruise lines. No explanation was given about who the reviewers were or how they were chosen, but it was clear to anyone who’s been around the cruise lindustry as long as I have that the results were skewed.

A recent survey by PhoCusWright of online travel review sites found that the traditional review sites like Tripadvisor are being supplanted by online travel booking sites as sources of consumer ratings and reviews. Of course, that doesn’t mean much considering that Expedia acquired TripAdvisor, Travelocity picked up IgoUgo, Priceline brought out MyTravelGuide and SideStep bought TravelPost (which in turn was acquired by Kayak and recently sold to a startup led by Expedia’s original founders).

The survey found that in the past couple of years — despite these acquisitions — more people are reviewing travel suppliers on the online booking sites than on the review sites. In 2008 52 percent of reviews were posted to online travel agent sites while only 46 percent were posted on traditional travel review sites. A year later, that relatively benign ratio has swelled to 74 percent for the OTAs and only 25 percent for travel review sites.

PhoCusWright explains the growing disparity this way:

There are several factors behind this shift in where travelers are posting hotel reviews. While category leader TripAdvisor’s review volume and unique visitor traffic both grew considerably in 2009, the OTAs have been aggressively building their portfolios of hotel reviews. They have significantly improved their processes for collecting reviews from customers. Most hotel and package bookers on OTAs receive some kind of trip follow-up communication soliciting their feedback, which feeds the hotel review pipeline.

And they have good reason for doing so: hotel review content appears to play an important role in the online hotel shopping process. Not only do more travelers identify hotel reviews on OTAs as influential in their purchasing decision than other types of online features or content, but OTA shoppers who visit hotel review pages are twice as likely to convert.

The question remains — should we trust our fellow travelers to post honest, objective reviews of the hotels, bars and restaurants they visit? I would give a skeptical yes answer, and here’s why: the more reviews there are, the less likely that the overall rating can be manipulated by fake reviews. Online travel booking engines obviously have recognized that — as well as the positive effect that ratings have on booking conversion — and therefore are striving to increase the number of reviews submitted by their clients.

So while it’s not a perfect system, it does have built-in checks and balances that only benefit by a higher volume of user-generated reviews.