The last time anyone in the lodging industry stopped to count, there were around 50,000 hotels and nearly 5 million guestrooms in the United States. I've never even seen a "reliable" guesstimate about the total number of hotels and rooms worldwide.

How many of the world's hotels and rooms have you stayed in? More to the point, how many of those establishments have I, your friendly neighborhood talking-head business-travel expert, stayed in?

I can't answer for you, but I can answer for me: Not nearly enough. At least not enough to suggest with any journalistic credibility that I know every desirable place—or even a desirable place—in every city, town, village, suburban office park, or airport on the planet.

So of course I consult user-generated review sites such as Trip Advisor and its many competitors for opinions on what hotels to visit and which to avoid. And it goes without saying that I urge you to do the same whenever you need guidance about lodging in an unfamiliar place or are in search of a new experience.

What is peculiar about those two statements is the vehemence with which many who claim to be professional travel experts would disagree. They are shocked—shocked!—to find that you'd listen to a gaggle of real people instead of hanging on their every pronouncement as if it is received wisdom from the hotel heavens.

"The whole emphasis on user-generated content is foolish," thunders Arthur Frommer, whose 1957 guidebook, Europe on $5 a Day, sparked the postwar middle-class travel movement. "I was the first person to use it [back in the 1960s]. Then we realized it was being massively manipulated."

"There has to be a better way to get authentic review about hotels," complains Chris Elliott, the syndicated travel columnist and radio host, who has done good work exposing some of the inherent flaws of Trip Advisor and its ilk.

The antipathy of professional travel journalists toward user-generated review sites is understandable, I guess. Nobody (including yours truly) likes someone doing for free what they get paid to do. Some, like Elliott, legitimately fret about the shortcoming of user-generated reviews, but forget that so-called pros have admitted to faking entire guidebooks. Others, like Frommer, simply can't accept that you might actually have your own ideas about how to travel and how much to spend.

A lot of the antagonism is also predictable. The same attacks were aimed at the Zagat Survey of restaurant diners when it first became popular in New York foodie circles in the early 1980s. As late as 1986, when I helped introduce Zagat's New York guide to business travelers nationwide via a story in Frequent Flyer magazine, there was a torrent of criticism from professional food writers who thought Tim and Nina Zagat would destroy "legitimate" restaurant criticism.

Twenty-five years later, smart business travelers know that sharing information is an exceedingly valuable exercise, and the Internet is an irreplaceable tool for doing it. As I've pecked around sites like Trip Advisor, Hotel Shark, Boo.com, Venere.com, and even user-generated commentary on the Web presence of the printed Fodor's guidebooks, I've developed a few rules of the reviewing road that I think would be useful to heed.

Aim for the Sweet Spot

Unlike Zagat's printed guides, which pasteurize and homogenize user reviews before we read them, user-generated Internet sites mostly post unfettered and unedited commentary from all comers. That means you need to separate out the extremes on your own. Ignore posts that can find no fault with a hotel and disregard those that can find no good. Somewhere in the middle is the generic truth about the quality of a hotel. And the more travelers who say the same thing about a property, the greater the chance that it is an accurate reflection of the state of affairs at a particular hotel.