I am a last minute'r. Basically it does two things
1) Keeps me from doing something stupid like coming back and bidding more.
2) Out bids the stupid.
Yes I know how it works, but there are many who don't. I have seen folks make 50 separate bids trying to find someone else’s max. I only bid once at the end and eliminate the idiot who keeps bidding a dollar more, a dollar more, a dollar more…...