I have to wonder why an article like this is even in the WSJ:

A Wall Street Journal investigation found that the Staples Inc. website displays different prices to people after estimating their locations. More than that, Staples appeared to consider the person's distance from a rival brick-and-mortar store, either OfficeMax Inc. or Office Depot Inc. If rival stores were within 20 miles or so, Staples.com usually showed a discounted price.

"How can they get away with that?" said Ms. Frizzell, who works in Bergheim, Texas.

Huh?  How can they get away with that?

They "get away with it" because you're an idiot.

You believe that when you go "online" you will get a "better" price.  You're a sheep.  You believe in the screaming signs in the window that say "40% OFF!" means you're actually getting a good deal rather than considering that it's quite possible the merchant doubled the price before taking the discount!

Airlines have done what they call "yield management" since, well, forever.  The guy in the next seat may have paid half -- or double -- what you did, depending on how or when he bought his ticket.

Perishable things (like airline seats) that have a value of zero if unsold beyond a certain time (when the plane leaves) are most-subject to this sort of pricing manipulation.  Indeed a savvy traveler (that would be moi among a few others) that understood how markets work used to be able to exploit that plus the fact that paper tickets had cash value to get out of a town when their flight was canceled or you had a sudden change of plans.  That 2 minutes just before the door closes on the plane was a ripe time for a traveler with a ticket that was supposed to be good for the next day, sometimes even on a different carrier, to show up at the gate.  Most of the time, if there were open seats, you'd get on board.

The airlines put a stop to this with "eTickets", which are one of the ways they******you.  By removing their effective value as currency, which paper tickets always had (even if at a heavy discount) this particular bit of hijinx has now ended, and both you and the airlines are poorer for it.  You, when you get caught in an airport.  The airlines, when the door closes and the seat is empty but would have generated some revenue.

People seem to believe that somehow the fact that a computer is involved and you're a "faceless person" behind a computer screen means you'll get a good deal.  That's such crap.  The tracking that is able to be done, even cross-site tracking thanks to advertising networks, means that whatever the merchant thinks he can get away with, he will.  And if he can get you to overpay, he'll do that too.

I love how people think that there's some magic behind the Internet.  The fact of the matter is that once you add in shipping there's a problem to overcome; it's much more expensive on a "per-unit" basis to ship one stapler than a whole case of them.  Guess who pays for this when you buy one through the Internet?  You do!  Now sure, you evade a trip in the car, and if the only reason for the trip was that stapler, it may be cheaper to use the Internet than the car, but if you had a bunch of things to buy it's not quite so simple.

There is no unbiased, impersonal Internet folks.