[lukeqsee]

Perhaps it's moderately inflated, but it is still the most well-known exchange among the populace; therefore, they're going to go with it. It's sort of like real currencies. Yes, on the spot market they're worth X, but when you're on the street trying to exchange it, it'll be worth X * 0.9.

[dmm]

It's inflated because USD withdrawals are severely delayed, often taking months to clear. There are people waiting since June 2013 for withdrawals.

Domestic JPY withdrawals seem to happen smoothly so some people use that route to get fiat out.

[higherpurpose]

It used to be where 80 percent of the transactions happened. Now it's more like 25 percent, and Bitstamp seems to have surpassed it recently, at least for BTC/USD:

http://bitcoincharts.com/markets/

[GigabyteCoin]

Exactly. Good luck getting 100% of the spot price of Gold.

In a perfect world the newspapers would use the combined weighted price for the last few weeks shared by all of the exchanges, but we're dealing with reporters here.