Definition of Bid Jamming
Bid jamming, sometimes referred to as "pinning", is a technique used in fixed-bid PPC programs like Overture / Yahoo! Sponsored Search to pay less than your competition for similar ad positions while holding their costs high. You "jam" your competitor by bidding one cent less than them, thus forcing them to pay their entire bid price for each bid while you pay one cent more than the bid immediately below yours. If the next bid is much lower, your competition can be spending substantially more for the higher ad position.
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