I've used Mac bids for a while and soon realized alot did make sense regarding bidding and the circumstances of getting out bid. I think it's pretty easy, if an item doesn't bring the bid they want a computer bids and u don't get the item. I would watch an item, and if Noone bids, u could come in at the end and bid and win it. Not so fast! As this happened as I would refresh my screen, an item that was previously 0 dollars would have a 300 bid. Noone would bid that, when they are the only bid and could have won the item for a dollar.