Apr. US population 2014 was 319 million.
Divide that by 4 as an average to get to households. About 80 million households.
Say 5% of these households buys on watch , that's 4 million watches.
Right...and I recall that Apple has likely sold less than 4 million watches in some older news articles. Again, it's a nice raw number that Apple sold a few million...sure...but as everyone stated before, Apple will sell a few million of anything they release simply because of the large population(s) and the Apple fans. But as a % of society? 5% is pretty sad. Granted it is year 1. But even still, what % of USA folks own a Mac? 15% on a great day...again, millions of units with nice margins but a minority of traditional desktop and laptop computers. iPhones of course are a much higher %.