Epinions is a website where people can review products. Users can register for free and start writing subjective reviews about many different types of items (software, music, television show, hardware, office appliances, ...). A peculiar characteristics of Epinions is that users are paid according to how much a review is found useful (Income Share program).
Also because of that, the attempts to game the systems are many and, as a possible fix, a trust system was put in place. Users can add other users to their "Web of Trust", i.e. "reviewers whose reviews and ratings they have consistently found to be valuable" and their "Block list", i.e. "authors whose reviews they find consistently offensive, inaccurate, or in general not valuable" (see the explanation of Epinions Web of Trust as backupped by Archive.org).