It has become the traveller's champion, a first port of call for holidaymakers in search of the warts-and-all truth about hotels and a place where they can let off steam when things go wrong.
But the world's largest travel website, TripAdvisor, is facing a searing backlash from hoteliers who claim it is rife with inaccuracies and fraudulent claims about their properties concocted by phoney reviewers.
This week, it was slammed as "despicable and cowardly" by BBC Dragon's Den panellist Duncan Bannatyne after he complained that a "dishonest" review compared his Charlton House Spa in Somerset to Fawlty Towers. He demanded that it be removed.
The website has also incurred the wrath of a growing number of Irish hoteliers over claims that it refuses to remove dishonest and defamatory reviews from its pages.
From the moment he set eyes on it, Joe O'Flynn knew there was something fishy about a TripAdvisor review of his hotel. As the owner of one of Wicklow's most successful country homes, Rathsallagh House in Dunlavin, he takes great pride in attending to his guests, especially those who come to stay at Christmas.
Last January, a new review popped up on TripAdvisor about his hotel written by a man who claimed he had just spent the holidays there. The vast bulk of Rathsallagh's reviews on the site fall into the "excellent" category but this was headlined "disappointing, food very poor on this occasion".
The guest stated that he was a regular visitor over the years but that his latest stay was a let-down. There wasn't enough turkey and ham, he claimed, and the Christmas pudding was not up to scratch.
He also complained about Joe, whom he claimed left the running of the day to his elderly parents and didn't make an appearance once. This surprised Joe as he had spent the entire Christmas on duty in the hotel making sure everything ran smoothly.
Because TripAdvisor protects the identity of its reviewers, Joe was unable to track down the name of the guest but he posted a reply on his review asking him to get in contact so he could address the issues raised. He was stunned by the mystery guest's response.
Despite his derogatory assessment of the hotel, the reviewer lambasted Joe for making direct contact and "attempting to breach the confidentiality of the website", which he said was "anonymous and should be respected as such".
He then went on to admit that he had never stayed in the hotel but knew of somebody who had. More remarkable yet, he signed off using his own name.
Joe circulated his name to all of his Christmas guests to see if anybody had heard of him but none of them had.
He then contacted TripAdvisor, told them about the fraudulent review and asked them to remove it at once. Despite countless efforts, one year later, it is still on the website.
"This man admitted in an email that he had never stayed with us in his life," says Joe.
"This is a breach of the TripAdvisor rules which state that reviews must be based on personal experience, not hearsay. I reminded TripAdvisor of that but they didn't want to know.
"I contacted them several times and asked them to remove it but my responses were just rejected. It seems there is one rule for TripAdvisor and another for the rest of us.
'They apply an adversarial censorship which is utterly biased if it comes to exposing holes in their system. I don't believe for a minute that they have the technology to sift out the false reviews from the genuine ones. That's complete bull."
Another popular proprietor of a Wicklow guesthouse is equally damning of the website, claiming she has been the victim of a malicious reviewer who never stayed with her but whose damaging report remains on the site despite numerous efforts to have it erased.
This owner is one of just hundreds of disgruntled owners planning legal action against the site for failing to remove fraudulent information from it. Online reputation services firm KwikChex, acting on behalf of more than 1,000 hoteliers including a number of Irish properties, estimates there are at least 27,000 defamatory comments on TripAdvisor which have never been tested for accuracy or truthfulness.
It intends to have them tested in court, a move which could spell the end of the website and dozens of others who facilitate the dissemination of anonymous, unverified reviews on the internet.
Its main gripe lies in the fact that anyone can post material on TripAdvisor without proof or confirmation that they have stayed in the hotel concerned. This leaves the website wide open to abuse by competitors and others who may have a grudge against a proprietor or their staff.
Hoteliers also say the website takes a guilty until proven innocent approach to them, and even when they produce evidence that a review is spurious, they are ignored.
But TripAdvisor rejects these claims, stating objections by hotel owners can be posted beneath every review.
"All hoteliers have an automatic right to reply," says Ireland spokeswoman Emma O'Boyle. "They can post a public response putting their side of the story across.
"We receive 29 posts per minute on the site but every single review is screened by our technology and anything that's flagged as suspicious is fully looked at by our team of content specialists.
"If the evidence proves categorically that the person had never stayed there, it would be taken down.
"But the truth is that if the vast majority of experiences people put on the site don't match the experience when they get to the property, people wouldn't keep visiting and we wouldn't have this phenomenal year-on-year growth."
Last year, TripAdvisor celebrated its 10th anniversary, becoming the first travel website to register 40 million unique visitors in a single month. It was set up in Massachusetts by an entrepreneur who had a brainwave after a visit to the travel agents to book a holiday in Mexico.
The US-based company makes most of its money from advertising by other websites whom visitors can link to from the site.
But what's to stop a hotelier from putting up glowing reports about their own property?
"That's very rare," says Emma, "but if we do catch a hotelier putting up reviews about themselves, we will stick a red badge on the site warning any prospective guests that this hotel has been under investigation for suspicious activity."
John Brennan, manager of the five-star Park Hotel in Kenmare, Co. Kerry, says: "I know of one property who ups itself all the time. The problem with TripAdvisor is that anyone can simply set up an email every week and build up their property again and again so they get close to the five-star mark.
"Equally they can butcher their neighbour, the competition or just someone they don't like. The website cloaks the identity of the person making the review so, in theory, I could spend all day writing bad reports about the Sheen Falls up the road.
"We get mainly very good reviews on the site but we have had fraudulent ones too. One man claimed that we had met him in the car park and told him to go away. That never happened. We went after TripAdvisor and they took it down.
"Another guy attempted to blackmail me by saying he would use TripAdvisor as a stick to beat us if we did not hand back what he perceived to be a hidden service charge on the bill.
'He had booked through an internet third-party site that has nothing to do with the hotel and had not bothered to read the small print. He went absolutely berserk at reception and said he would tell the world if we applied the charge, which we did.
"He wrote his review. It is still there and it is the only one I have responded to online."
But even John Brennan, an experienced traveller, admits he relies heavily on TripAdvisor when planning his own holiday.
"I travel extensively and use it all the time. I would value 80pc of its content as being the truth. If a place is getting consistently bad reviews, there's no doubt that something is going wrong.
"I always look at the number of contributions made by each reviewer. If a hotel has a lot of reviews made by single contributors, I don't trust that. You don't get people going in to the website to put up just one review so I would have doubts over a property with a whole load of single reviews from single contributors.
"But on the whole, I am in favour of TripAdvisor. It has brought information to the public in a way guide books were never able to do.
"If it identifies problems that need to be addressed, that can only be good for the tourist industry and the traveller."