Every month, 150 million people around the world consult sites like TripAdvisor. But can you trust the guide? From the click factories in Madagascar selling good reviews to restaurants being sabotaged by scathing comments from people who have never visited, it’s estimated that 10% of the reviews posted on Trip Advisor are fake. And what about the discounts offered if you make a reservation via certain websites? Are they really what they seem? We investigate.