How does proxy bidding work?

We use proxy bidding for our Expired Domain Auctions, User Auctions and Backorders (if they go to auction). Here is how it works:

Say for example, a domain is in auction with a starting bid price of $12.99.

If bidder A places a bid of $20.00 for the domain, our system will start his bid at $12.99 and bid up to $20.00 automatically on his behalf.

When bidder B visits the auction, he sees the current bid price as $12.99. If bidder B decides to place a bid for $14.00, he will be outbid immediately by bidder A, and the new minimum bid will be $15.00. In order to outbid the first bidder, he would need to bid at least $20.01.

If bidder B places a bid for $20.00, which matches bidder A's maximum bid amount, then bidder A would still be the high bidder, but the new minimum bid would be $21.00.

If an auction price reaches $50, proxy bids will be tiered based on the current high bid.

How do I place a bid on an Expired Domain Auction?

How do I place a bid in the 3-5 day auction that sometimes follows a successful backorder request?