Re: [Vo]:[OT] 740,000 Bitcoins Missing

[Craig]

Coinbase isn't an exchange, but rather a market maker for Bitcoin. You 
buy and sell bitcoins from them at agreed-upon rates; unlike an exchange 
where you place 'buy' or 'sell' orders against other account holders' 
orders.

Here is Coinbase's method of keeping Bitcoins in cold storage; which is 
what MtGox claims to have failed at providing.

http://blog.coinbase.com/post/33197656699/coinbase-now-storing-87-of-customer-funds-offline

Craig