One of the biggest problems with online travel reviews is that more often than not they are not scrutinized by humans before they are published. A software program checks for flagged words such as obscenities and for spammy links and if a review passes these checks it is automatically approved. Reviews are free content and the bigger the site, the greater the traffic and thus the bigger the revenue. This is the logic.
TripAdvisor has been pursuing this business model and has recently got into trouble. Hotel managers and other accommodation providers have reported being blackmailed by customers asking for discounts or they will write bad reviews about a business.
There is plenty of room for abusing this automated review system. Hotel owners and tour operators can write bogus good reviews about their own businesses. Alternatively, they can write bad reviews about their competitors. If you look at booking sites like hostelbookers you see widely contradictory reviews. It doesn’t seem like the reviews refer to the same places.
There are a number of solutions to these problems. the first is obviously human screening. This is not fool proof but it will weed out the most obvious offenders. A better method is to only let actual customers of services review places. For example the r24.org system only allows people who have actually stayed in a place and paid with a credit card enter a comment. Thus sites like samuiaccommodation.info has links to reviews of Koh Samui hotels by people who have actually booked accommodation on Koh Samui.
The final solution is for the reader of travel reviews to be more critical, to take an overview. If only one person complains that their room was dirty whereas all the other reviews say the hotel was clean or make no mention about hygiene then you should discredit the one rogue review.
As with much information on the internet online travel reviews should be read with a pinch of salt and a good deal critical deliberation to separate the real review from the fake and malicious review.