Trip Advisor Reviews
Do you read them, or contribute with reviews? I know in the past some establishments have suffered due to bad reviews that they said were fake and posted out of spite, but in general Trip Advisor is quite good for reviews, plus you can ask questions. Usually I read the reviews on the site first and filter to the poor and average ratings first. Sometimes you do need to look at the dates though because places can improve.
Many establishments do respond, especially if it was a poor review and I have been offered gift vouchers and one hotel offered me a free stay. The voucher never turned up, and I haven't taken the hotel up on the offer of a free stay as I haven't been in that area for a while. The majority of reviews are genuine and because people can post their actual photos, pictures can speak for themselves.
You may not know this if you don't write reviews on Trip Advisor but they do offer from time to time discounts if you book accommodation through them. I also post reviews to help others, and if it's a bad review it can help the establishment know how they can improve.