From hotels and holiday destinations, to gadgets, cars and restaurants, online reviews written by the ordinary Joe are playing an increasing role in what we choose to buy.
A study this year by Weber Shandwick found that 83% of consumers say online reviews influence their perception of a company.
Another study this year by the University of California, Berkeley, found that even a half-star increase in rating corresponded with an increase in the number of dinner reservations at a restaurant.
But with consumer trust in online reviews so high, it's little wonder that there is a growing market for fake reviews. These reviews are written by hired hands who, for a small fee, turn out a positive review on the pretence of being a real customer. They are often well written, meaning that they can be hard to spot.
According to tech research company Gartner the problem is only going to get worse.
In a study out last month, it predicted that by 2014, between 10 and 15 per cent of social media reviews will be fake and paid for by companies.
"Many marketers have turned to paying for positive reviews with cash, coupons and promotions including additional hits on YouTube videos in order to pique site visitors' interests in the hope of increasing sales, customer loyalty and customer advocacy through social media 'word of mouth' campaigns," said Jenny Sussin, senior research analyst at Gartner.
Todd William, founder of reputation management company Reputation Rhino, blames the surge in fake online reviews on competition.
"This study confirms what reputation management experts have known all along - the fierce competition for a positive online reputation has led many companies to fake their way to the top on Google Places, Yelp, Tripadvisor and other popular social media destinations," he said.