“Just ask happy customers for reviews” is everywhere as advice. The problem: the rules are different on every platform, and following the wrong one can get your reviews hidden — or your business flagged. Here's the plain-English version of who allows what.
Google: ask away — just don't cherry-pick
Short version: Asking is fine. Steering only happy customers is not.
Google is happy for you to ask customers for reviews. What it forbids is “gating” — only funneling the happy ones to leave a review while screening out the unhappy ones — and any kind of paid or incentivized review. Cross that line and Google can remove all your reviews. So ask everyone, the same way.
Yelp: don't ask at all
Short version: Yelp actively discourages solicitation and filters reviews it thinks were requested.
Yelp is the opposite of Google here. It asks businesses not to solicit reviews, and its software quietly hides reviews it suspects were prompted — even genuine, positive ones. On Yelp the move is to earn reviews naturally: a great experience, a complete profile, and replying to the reviews you get.
TripAdvisor: ask, but never sweeten it
Short version: Asking is allowed; offering anything in return is penalized.
If you're in hospitality or travel, TripAdvisor lets you ask — but offering a discount or perk for a review can get reviews removed and a warning badge slapped on your listing. Steady, genuine, recent reviews are what it rewards.
One blanket review policy across every platform is how good businesses accidentally get penalized.
Where this comes from: the published review policies of Google, Yelp, and TripAdvisor. Rules change, so when in doubt, check the platform's current guidelines — but the broad differences above have held for a while.