[amitsy]

Yes, there is that danger but we have not seen that happening as of yet.

Users are only asked for positive reviews

[beachy]

If you are successful, then next I suggest you will be following in the steps of vendors offering online reference checks, e.g xref, checkster.

You will need all sorts of fraud detection, e.g multiple reviewers all coming from the same ip, and your customers will pay for that security.