Yeah, this is a very good point. I'm not sure how this will translate with the PS4 and XB1, but the xbox 360 was massively successful - NA is the most lucrative market for video games in terms of unit profit so with that being the case, the console was objectively a huge success. Overall sales slightly favored the PS3 (nobody bought the 360 in japan), but nonetheless the 360 did very very well.
What will be interesting is seeing if the following for the 360 will translate into high sales for the XB1 in NA. I'd say the 100$ price difference will make that improbable from the get go but it really depends on supply issues. And the price differences will even out over the lifetime of the consoles since GDDR5 is still very expensive and the BOM of XB1 will lower at a faster rate as compared to PS4. At some point in the future, both of these systems will either be at price parity of the XB1 may be cheaper. I can certainly guarantee that the BOM for the XB1 will lower MUCH MUCH faster than it will for the PS4 due to GDDR5.
I dunno. It's hard to declare a winner thus far. NA being the most lucrative market is still up in the air, and that battle is for the "long haul". Japan will certainly favor the PS4. Europe, probably PS4. It does seem that PS4 is the better pure gamer's machine but, the other features of the XB1 could win quite a following too - MS just needs to fix the functionality of Kinect and do so fast.