They need to do controlled trials whereby they try their best to truly and objectively measure a sample and then compare those to real ratings. I suggest that

They need to do controlled trials whereby they try their best to truly and objectively measure a sample and then compare those to real ratings. I suggest that for most things, customer ratings are completely irrelevant. They might want to ask specific, relevant questions, such as: "Was the car/flat generally clean and tidy" "Were there any problems entering the facility" on the customer side "Did the customer generate problems with the authorities" "Did the customer disrupt your ability to drive" "Did the customer make repeated requests for out-of-bounds services even when they were informed such requests could not be fulfilled" "Did the customer party include more individuals than indicated on the reservation" etc. etc. Then they can glean specific bits of information and provide guidance. Otherwise, general reviews are pointless because they're muddy, set to different standards, emotional, unspecific etc.