Big part of me thinks it's Steam giving the discount out if their own pocket. EA are thinking they'll get full price per unit but Steam are willing to take a slight hit to make sure as many units as possible are sold through them...They're setting up to kill Origin...Either that or EA are just mean, dumb people....
It is Valve's shop, so it is of course Valves decision to grant the discount.
The point many are missing is that Mass Effect 3 is only available for less than a year on Steam.
So it is a discount for people that only very recently brought the game.
