Google Maps stopped being a reliable way to find good restaurants a long time ago. Any time in my city when I see a place with a high rating and suspiciously large number of reviews, searching for "five stars" in the reviews inevitably finds customers helpfully mentioning that they got free food in exchange. I've even seen places advertise the bribe openly on Maps. It would be trivial to detect this and punish offenders, but Google chooses not to.

I've been mulling over starting a boutique social network focused on location reviews with real life friends exclusively.

I've seen several places that have a note printed on their menus offering a discount for a positive review.