DaveN writes Yahoo! Overture Bid Jamming is "when you raise your bid amount to just a penny below the top bidder." So basically if your competitor ups a bid to $25 and the next two highest bids are $5 and $4, all you need to do, is raise your bid to $24.99 and that will ensure that your competitor pays. DaveN says;
#1 is 25 ( what they pay is 5.01 ) <- silly boy !
#2 is 5 ( what they pay is 4.51 )
#3 is 4.50 (these guys pay .10 )but you want to play in this keyword. So if you bid 24.99
#1 is 25 ( what they pay is 25.00 ) #2 you 24.99 (but you pay 5.01) <- Bid Jamming #3 is 5 ( what they pay is 4.51 ) #4 is 4.50 (these guys pay .10p )
Forum discussion on this basic but important topic at Search Engine Watch Forums.