How do Sniping and eBay Proxy Bidding Work Together?

First, you need to understand how eBay "proxy" (automatic) bidding works. When you place a bid, you enter the maximum amount you're willing to pay for the item. When someone else places a bid, eBay will add one bid increment to the price that is showing at the time of the bid. eBay will bid only as much as necessary to make sure that you remain the high bidder, or to meet the reserve price, up to your maximum amount.

Helpful Tip: For auctions, eBay always calculates the price by taking the second-highest bid and adding a bid increment.

For eBay's explanation, see their page for proxy bidding.

Here's an example:

1. The current bid for an item is $10.00. Tom is the high bidder, and has placed a maximum bid of $12.00 on the item. His maximum bid is kept confidential from other members.
2. Mary views the item and places a maximum bid of $15.00. Mary becomes the high bidder.
3. Tom's bid is raised to his maximum of $12.00, but not higher. This is the proxy bid. Mary's bid is now $12.50. If he doesn't raise his maximum bid, Mary wins the item.

Now add sniping into the picture. Sniping doesn't do anything fancy in addition to what you read above. BidSlammer just places the bid at the last second, exactly as you would if you placed the bid yourself. eBay's proxy bidding system kicks in to handle the rest--- that is, eBay will make sure you only pay the minimum amount necessary.