Let's all remember the fact that most movies make more from dvd-broadcast-rental-ppv etc, (ie, the back end) than they do from Box Office. Plus there is the staggering amount of licensed material associated with Kong. Much like the SW prequels KK was probably paid for (or close to) by licenses alone! Not to mention they've already released a DVD of the "making of" to get the whole DVD ball rolling!
Kong was a financial disappointment only in the same way that realizing you have to pay taxes on Lotto money is a disappointment!