A consumer watchdog about at by for in of on to the UK has reported that many Internet sites are full about at by for in of on to fake reviews. The UK's Competition and Market Authority (CMA) believes there are millions about at by for in of on to reviews about at by for in of on to sites about at by for in of on to hotels, restaurants, theatres and online stores that have been paid about at by for in of on to to trick shoppers. It said at least 25 million people about at by for in of on to Britain read reviews on websites such as Amazon and TripAdvisor before booking holidays or doing online shopping. The CMA found there was a growth about at by for in of on to the industry that writes fake reviews about at by for in of on to companies and businesses. Many companies wrote fake reviews about at by for in of on to themselves as a marketing tool. Others offered money, free samples or upgrades in exchange about at by for in of on to five-star reviews. Online reviews are very important about at by for in of on to businesses. Industry analysts estimate that about at by for in of on to Britain alone, $36 billion a year about at by for in of on to consumer spending could be influenced about at by for in of on to online reviews. A CMA spokeswoman said: "Millions of people look about at by for in of on to online reviews and endorsements before making decisions such as where to stay about at by for in of on to holiday or which plumber to use." She added: "We have found that consumers who use online reviews and endorsements find them valuable, but we have also heard about some practices that may be unlawful." Some about at by for in of on to the more illegal activity includes rival companies posting negative remarks about at by for in of on to each other's goods and services. Bosses could face going to prison about at by for in of on to doing this.