Guests can't post reviews on trivago because trivago is a hotel metasearch, not a booking site or a review site.
When travelers find and select a deal on trivago, we direct them to the advertiser of that deal: a third-party booking site or a property’s website. That's where they complete the booking process.
After guests stay at a property, they're asked to rate their stay by the booking site where they made their reservation. All reviews and ratings shown about your property on trivago are collected from those third-party sources.
You can stay up to date on your online reputation by regularly referring to your trivago profile. We highly recommend that you use the data to your advantage: promote what you excel in and improve what needs a bit more attention to get ahead.