i think alot of people on this site dont understand what a "casual" gamer is.
its the 8 year old boy who plays Minecraft & Skylanders. the 12 year old girl who plays Just Dance & Style Savvy. the 19 year old college kid who plays Call of Duty or FIFA with his roommates after class. the mom who plays Mario Kart to bond with her kids. the the lapsed gamer who doesnt play nearly as much as they used to because of work/family/etc but still plays occasionally to wind down and relax. and yes its the grandma who plays Wii Fit to try getting in shape.
all the comments like, "Switch cant sell Wii numbers without a Wii Sports level success", just dont make sense.
what a device needs in order to be a "casual" hit is to have an accessible/convenient concept with an effective marketing/advertising campaign, a price point that the market finds acceptable for what the device offers and a steady flow of software that appeals to multiple demographics.
whether or not Switch meets all these criteria and will be a huge success remains to be seen but considering that 3DS+Wii U will reach 85 million while not hitting all those critera than i dont think 100 million is out of the question.
When the herd loses its way, the shepard must kill the bull that leads them astray.
