Haggling is a common form of buying and selling goods all across the world, and it's almost a given at yard sales and flea markets. However, the online shopping sector has no haggling whatsoever -- you either pay the price the seller lists or don't buy it. That might change, though, because Amazon filed a patent for an online haggling system of their own.
Amazon's haggling system allows buyers and sellers to interact with one another and make offers and counteroffers until both parties are happy with an agreed-upon price. It would work pretty much the same way if you were trying to talk the price down to $20 for two pairs of those fancy knock-off sunglasses at your local flea market, but only this time there's no awkward face-to-face interaction.
Amazon also proposed a unique rating system that it would put in place for both buyers and sellers. Ratings would be based on flexibility, average closing prices, and how likely either side is to drop a deal before it's done. This kind of rating system would easily weed out all of the bad apples and cheapskates that might low-ball every offer.
Whether or not Amazon will actually launch an online haggling system is still unknown. It wouldn't be the first time that a website has implemented the same kind of system, though. eBay has their "Best Offer" feature, where buyers can make their own offers on auction listings if the seller has the feature enabled.