In my proxy days, and when the mood struck, I did something similar. I’d come in the last couple of days of an auction and little nibble my way up to high bidder, and then leave several more bids – even up to 100. You only need to increase your proxy bid by $1 to leave 100 one-cent higher bids. Even leaving 10 $5 increased bids will make things look off (or abnormal), and on a $500 auction that isn’t all that much money. It’s weird to see someone place 20 to 100 consecutive proxy-bids. I suspect that for some people, they think something is wrong and stay out of the auction. I suspect for other people, they see this as a challenge, and decide they are going to win. Maybe they’ll want to see if you are bluffing. Maybe they’ll turn a bidding war into a bidding crusade. Maybe they’ll talk about it on a sniping forum. This did cause me a bid-retraction, or two. This also caused me a question, or two from sellers. Why do it? Why not?