What if the auction ended, not at an exact time, but at some unknown time that could be as much as a half hour plus or minus from the nominal end time?

When ebay first started, I remember they used to have a "going going gone" period like a real auction. The end of the auction gets extended if there are late bids. So if someone was trying to snipe a bid, the act of trying to snipe actually extended the auction and allowed others in after you.

Did they stop doing this, and why?

(I think this very question has already been answered in a similar bid-sniping thread a while back on the BBS, I just don't remember the answer.)