I almost never see the following taken into consideration when comparing PS4 and Switch sales:
When counting PS4 sales, for reasons that should be pretty obvious, PS4 Pro sales are counted. A Pro is something that could sell to vanilla PS4 owners looking for an upgrade. There's also the slim which could appeal for someone looking for a slimmer model.
The Switch has no Pro model or slim model, there's only one model so far. In addition, the 3DS is still selling which not only appeals to someone looking for a mobile option, it also appeals to buyers looking for hardware that can play Nintendo's games. The 3DS has a Mario Kart as does the Switch.
These two aren't the only pieces of hardware Nintendo is selling: the NES Mini and SNES Mini have been major sellers last I've heard which could also potentially lure people looking for Nintendo games away from buying a Switch. Someone looking for a Mario game could pick up a Mini instead of a Switch for example.
Sony has the PS Mini but I understand reception of that hasn't been the best and, I imagine, its library is quite dissimilar from the PS4's. I doubt the PS Mini is luring many away from buying a PS4...
I should make clear that often times, I see some impressed by the PS4's sales. One can see this happening through http://gamrconnect.vgchartz.com/thread.php?id=239744.
For whatever reason however, no potential caveats are ever brought up. I have yet to see any mention of PS4 and PS4 Pro sales figures being lumped in together for example.Last edited by KLAMarine - on 01 April 2019