Well you only ever get a low percentage of people who buy a game going on the forums for it. With a large chunk of that tech support or gameplay advice. Given the nature of the game, the plethora of competition in the 4X market and the fact it was never retail 5,000 isn't impossibly low.
The revenue figues, well such things are for PR, it's not lying just artistic licence
So if you include total revenue and shipping you get a high value, if you take off taxes and shipping you get a low value. It's a niche(ish) product and you want publicity, which would you chose to use?