It's really simple, I'm not sure if it was posted or not.
It works allows you to buy some items you want cheap or just make profit on good ones.
What you do is sort items by time left and watch these auctions that are about to end. It's funny how much auctions are ending at the same time. You might want to skip few first pages with 1minute left since those are with seconds left, they usually end before you get to read their stats. Most people overprice on buyout and underprice on bid and since its just seconds left if you're fast, You get what you want.