TripAdvisor has responded to criticism about the authenticity of its reviews saying it believes they are "authentic, honest and unbiased". Sunday Times said one hotelier in Spain claimed her ratings tumbled because of a critical review from a rival, while a former West Country hotelier claimed to write their own reviews. But a spokeswoman for Expedia-owned Trip Advisor said: "The vast majority of hotels understand the tremendous risk to their reputation and their business if they attempt to post fraudulent information on review sites like TripAdvisor.
 
"As such, attempts of this nature are rare on TripAdvisor, but we take serious steps to penalise anyone caught attempting to trick the system. In the event that a review is suspected to be fraudulent, it is immediately taken down, thereby affecting the business’s ranking in the TripAdvisor Popularity Index.

Further measures to penalise those attempting to trick the system are handled on a case-by-case basis, but can include sending a warning letter to the property owners and posting a notice on TripAdvisor to warn travellers that a particular property is being investigated for potentially fraudulent activity."

She also said the sheer volume of reviews for any individual property allows travellers to base their decisions on the opinions of many and provides an additional safeguard.

TripAdvisor research shows the average traveller reads three pages of reviews when researching a hotel. Every review is screened before posting and a team of quality assurance specialists investigates suspicious ones. Automated tools help identify attempts to subvert the system and its large community also help to police content. In total, the site features some 25m reviews and opinions.