The advent of online travel sites has been a thorn in the side of home-based agents for some time now, but an experienced, well-traveled agent can turn the online invasion in their favor. For instance, have you ever had a client come to you with a specific hotel in mind that they read about on TripAdvisor? As most agents know—and as the Associated Press reported this week—TripAdvisor and other travel review sites can be victims of false reviews. These can either be negative reviews from a competitor or other third party with an ax to grind, or glowing reviews from someone inside the hotel.

To TripAdvisor’s credit, the site has been quietly but diligently flagging disclaimers that warn customers of hotels writing fake reviews to improve their popularity rankings or hurt competitors. Still, the mere presence of those disclaimers show that TripAdvisor has a problem with fake reviews. Other sites such as Yelp or Priceline can be subject to the same situation.

Agents should stress the importance of personal experience they can offer their clients—either firsthand knowledge of a property or referrals from other clients. Advise them that these sites can be a good preliminary guide, but in the end they should put their faith in a professional. It’s too easy these days for travelers to base an entire trip on relatively anonymous information from the Internet—and it can be a costly mistake. Remind your clients that they don’t want to be the ones writing the next negative post on TripAdvisor.