That's how some companies manipulate trust scores and ratings on a few platforms like Trust Pilot. Suppose, A casino like 1xBit scamming people every day. Everyone doesn't rate them on Trust Pilot or so. If 1xBit starts buying fake reviews.
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1xBIT has already done that, both on this forum and on the TrustPilot platform. They were paying members for fake reviews on bitcointalk as part of their "honest" review campaign, as for Trustpilot, they admitted inciting users to write reviews.
We offer our players a gift, and ask them to leave a reply on TrustPilot - it is not necessary to receive the gift, but most of the people leave small replies.