The most remarkable detail of this C-Class sales beat up against the 3-Series is that fundamentally this C-Class is the same as the 2007 C-Class. In other words, the facelifted C-Class sells more than the new 3-Series. By a quite lot.
To me, the only explanation is pricing. And like I said before, this 3-Series was priced out of the segment too soon, too quick and without real substance to this price increase.