It does, but on occasions it can backfire, sometimes instead of stopping just over a realistic price, or going way over your bid, sometimes they just stop short of your bid, like £24.50 now that is annoying. I once saw a slightly creased William III 1701 (I think) half guinea in F, with a slight dint right near the edge, go for an amazing price, i was fighting them for it right up to £250 (which is above book price, but the book price on these things is never precise, they always sell for more, cos you don't see them anywhere, not in grades lower than EF those coins that go for thousands), after £250, and upto £300 i just kept putting bids on to make the price go up. I'm not kidding, before i clicked the button to type in the bid it was £220, after i'd submitted the bid it was already outbid and the price was now £275, i never actually made it to top bidder. There must have been at least four of us fighting over it. It went for about £375-£410 in the end which is way way over the catalogue price, i definately wouldn't have paid a penny over £250 for it (unless i'd won it by accident). Infact it was probably only worth about £110-150, but when i get going on ebay i can't sop myself, it's the thrill of the bid. No wonder i don't go on ebay anymore.