lolz.
You'd think that Blizzard would have learned from the American launch of the game. The same exact thing happened then, they sold about 400,000 units by the end of the first week, and it caused all sorts of problems which are almost all gone, there are still a few issues but they're minor compared to all the crap that happened at launch.
But, yeah, I think it says something about a company when they expect to have 600,000 users by the end of the first year but they get them all by the end of the first week. And, also, for them to sell more units than the size of the predicted market.
I challenge someone to find a company that always does what Blizzard does (constantly release amazingly polished games that are instant bestsellers, and are still updating games that are 8 years old, create games that are more addicting that drugs, cigarettes, booze, and sex COMBINED), because I honestly don't think there is another one out there like it.