Now, we all know that according to Blizzard these money are used for server maintenance, support, and ongoing content creation. We also know how most of the time servers are down, especially when new expansion-packs rush in (remember The Burning Crusade fiesta?...). After some googling on the Internet we've also discovered that the most expensive data center to date is the one Microsoft tries to built somewhere in Texas, which is to cost around US600 million (and yes, it's going to be gigantic, much larger than anything Blizzard has at the moment...). So building and maintaining server centers shouldn't surpass US100 million/year, and that's a worst case scenario...
Going further with our infamous judgement, we infer that it costs around US 10 million to build a PC game these days (Halo 3 apparently cost between US 25 and US 40 to build, and US 10 million more to promote, but that's an exception) and that offering support for it shouldn't cost more than US 10 million (come on, it's a friggin' game, I know it's got 10 million subscribers, but not all have issues and it's not like Blizzard answers your questions the same day you asked them... if they answer...).
What does the total amount to? Well, US 100 million in servers and maintenance plus about US 20 million for content creation and support... you guessed it, about US120 million per year, and only if one expansion pack is released annually...
Where does the rest until US 1.7 billion go to?...
Sponsor
