Online reviews can play an important role in helping consumers make the right choices.
In order to maintain people’s trust, review sites should check and present reviews in a way that avoids distorting the overall picture presented to people that read them. If your business’s website allows people to review products or services – whether they are yours, or someone else’s – you should publish all genuine, relevant and lawful reviews. You should also make sure that your processes to collect, moderate and publish reviews don’t hinder this. Updated February 2016
An interesting contribution from the UK CMA on the topic of online review sites - Also named "60 second summary" to get updated on the guidance and recommended practices. Should be applied by any e-commerce site and marketplace to build trust with customers.
https://www.gov.uk/government/publications/online-reviews-and-endorsements-advice-for-businesses