sellers use automated shill bidding bots on auction websites to
unfairly inflate the bid value of an item to be sold. Shill bidding
is also used with no bids or interest from the buyers, creating an
artificial interest on the item.
submit very high bids to discourage other bidders from competing
for the same item, then retract their bids so that people they know
can get the item at a lower price.
contact bidders and offer to sell them the same item they are
currently bidding, thus luring bidders off legitimate auction
sites. Bots are used in bid siphoning to stealing the bidders'
contact and bid information from auction sites.