The Advertising Standards Authority (ASA) said TripAdvisor misled visitors to the site by posting claims the website contained trusted, honest reviews from more than 50 million genuine travellers. ASA said the claims had not been substantiated. It ordered TripAdvisor not to display the information again.
The watchdog issued its ruling after receiving complaints about the claims made by TripAdvisor. The complaints were made by two hotels and by KwikChex, a firm that accredits business standards. They had argued that the claims could not be proven because they understood TripAdvisor did not verify the reviews posted on the site and could therefore not determine whether they were genuine or from real travellers.
ASA upheld the complaint after finding that reviews could be posted on TripAdvisor "without any form of verification" meaning that it was "possible that non-genuine content would appear on the site undetected".
Even if visitors to the site had a "healthy scepticism" of review postings and even though hoteliers have a right to respond to negative or critical comments, consumers may still find it difficult to "detect and separate non-genuine reviews from genuine content," ASA said. A hotelier's response "in itself" would not be sufficient "to alert consumers to, and moderate, non-genuine content," it said.
"Because we considered that the claims implied that consumers could be assured that all review content on the TripAdvisor site was genuine, when we understood that might not be the case, we concluded that the claims were misleading," ASA said in its ruling.
Under advertising rules set out in the UK Code of Non-broadcast Advertising, Sales Promotions and Direct Marketing (CAP Code) marketing communications that "materially mislead" consumers or are "likely to do so" are prohibited.
Marketers are also required to have "documentary evidence" in order to prove claims they make in ads. That evidence must be "likely" to be considered as "objective" by consumers and be "capable of objective substantiation". The CAP Code says that the ASA "may regard claims as misleading in the absence of adequate substantiation".
In a statement KwikChex said it 'knows' that a "substantial number" of reviews posted on Trip Advisor are "false" and that "this has been proven many times". As a result TripAdvisor's claims were "exaggerated" and "unsubstantiated," it said.
The business standards assessment body said it has proof that businesses have engaged in artificially promoting their service through fake reviews on TripAdvisor and would be releasing the information.
"In terms of fake positive reviews, we will be releasing evidence of precisely how the few checks and systems that TripAdvisor have in place are being circumvented to manipulate the rankings," KwikChex said.
"This will also lead to identification of some of the businesses employing 'professional' review fraudsters. We will be providing this information to both TripAdvisor and the relevant authorities in a bid to help stop such practices. In exchange we will be asking TripAdvisor to prioritise examination of cases brought to us by our members which have clear evidence of defamation, malice and gross distortion," it said.
Under the UK's Consumer Protection from Unfair Trading Regulations pretending to be a consumer and giving yourself a positive review is 'an unfair commercial practice'. This is a criminal offence and business proprietors are potentially liable for an unlimited fine and a prison sentence of two years.
The practice, known as 'astroturfing' as it fakes grass-roots support for a product or service, is also contrary to the CAP Code. Astroturfing breaches the CAP Code as the marketing is not fair, legal, decent, honest and truthful - the key principles of the self-regulatory CAP Code.
ASA can refer misleading advertisers to the Office of Fair Trading, the consumer protection watchdog, which has the power to bring legal proceedings for breaches of UK consumer protection laws, although such referrals are rare.