You are right, my suggestion involves the lowest hanging fruit where one can purchase unlimited positive or negative reviews from unrelated parties.

I can google a far away barber who has accumulated 17 reviews over the last 10 years. Google then allows me to shit talk the guy for the world to see. 2 minutes of effort and its free! They get to carry it around like a badge of shame forever.

You should give me a discount or ill post a negative review and unleash the roaches on your hotel. It would be rude if you didn't.

edit: I think a digital ID would be useful for real reviews.