Blizzard's programmers develop a game in the US. It's hosted on US servers. It has an in-game currency system/DLC system, also hosted in the US, and processes card transactions in the US.

However, at the same time, they claim that the entity that runs the DLC purchase system is in Malta, where Blizzard has no employees, but uses an outside legal and accounting firm.

They claim all the value is in Malta.

I tend to disagree.