Ok, so lets be clear about things:
According to VGC in January 2010 http://www.vgchartz.com/monthly.php on a worldwide basis ME2 comes in at 5th position. It has a sales ratio of 6:1 for january with Forza Motorsport 3, which is at position 31. that means positions 6-30 all sold at better than a 6:1 ratio.
Now taking 360 only for January there were a total of 6 games that sold between ME2 at the top and FM3 in the 6:1 ratio position
So lets look at 360 only for january for the Americas: ME2 is in 2nd position, and the game in the in the 6:1 position is Army of two 40th day (PS3) at 19th. Between ME2 and position 19 there are 6 Xbox 360 games whose sales ratio to ME2 are better than 6:1.
I can't see where a 6:1 ratio for January game sales can come from even if you only consider XBox 360 sales.
The only 6:1 ratio I can find is for the week ending 30 Jan http://www.vgchartz.com/weekly.php. In that week ME outsold all other 360 titles by 6:1. And of course it outsold everything that week, but no where near 6:1. Even it's nearest HD rival was MAG at 3:1. Against DQ VI it was a statistical tie, pretty much 1:1.
So not only is the title unclear, but the source information itself is incorrect (or poorly worded making it ambiguous).
Edit: making the analyst being quoted arguably worse that Pachter. Pachter makes bad predicitions, but normally his analysis of what's already happened is factually correct, even if the conclusions he draws from those facts are debatable.
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