If you enter your maximum bid in ebay you're revealing it. With sniping no one can discover your maximum bid.
The 'nibblers' will invariably show up and bid small amounts until they exceed your maximum bid, while not revealing theirs.
The 'nibblers' will invariably show up and bid small amounts until they exceed your maximum bid, while not revealing theirs.
A bidding war can make the perceived value of an item increase.
People's competitive behavior, or "you're not taking this from me," or "I've definitely got this item and have made plans" or any number of other emotional behaviors take over.
People's railing against sniping also demonstrates this.