It's actually just like an auction where everyone is bidding by proxy. In this case, the eBay servers would be your proxy, which is exactly what they do now. In fact, now that I think about it, it's exactly like a silent auction.

The only thing that re-bidding really helps with is if you made a mistake, or if you don't want someone else to get the item out of pure spite.

Oh, and the definition of an auction is ``a sale of property to the highest bidder'' (Merriam-Webster). I cannot find a definition that requires the type of back-and-forth that goes on in Sotheby's-type auctions.