why did mass effect 2 only sell 2.3m on 360?

[dsage01]

Machina said:

What did you expect?

It's tracking nicely above the original and well on course for 3 million lifetime. I loved the game, and I wish it was doing the numbers Gears manages (and Gears did Mass Effect numbers, or worse, much worse...) but it's unreasonable to expect that.

When did Gears do worse than ME? When did it not do better than ME.