And even then, it still doesn't come close to validating the MSNBC report's claim of it selling 3x as much as other PC games this year, as it still wouldn't be the highest selling PC game this year.
Actually the report was not a claim, it was a report. I believe, if you watch it I will be validated, this was a statement that Valve released that they were reporting. I guess Valve would know, considering they own Steam.
As far as units shipped. I guess that wouldn't mean that every unit was sold. But I'm not sure how it all works. It is possible that stores pay for the copies when they get them? I don't know. In any event the game is a huge success, $650 million is a huge number. Perhaps it is less. Nevertheless it still has to be a huge amount.