I was thinking primarily of older people; the odds of owning a smartphone decrease as you go into the 50+ age brackets, and cell phone ownership in general fall

I was thinking primarily of older people; the odds of owning a smartphone decrease as you go into the 50+ age brackets, and cell phone ownership in general falls off as you go into 65+ (http://www.pewinternet.org/fact-sheets/mobile-technology-fact-sheet/ http://www.pewinternet.org/fact-sheets/mobile-technology-fac...). That Pew page states that 10% of American adults still don't own a cell phone, but of those who do, I would expect there's a healthy percentage for whom the cell phone is infrequently used as an emergency contact system, or just-in-case for road trips, or for the occasional phone call. (They don't have numbers on usage patterns though.) I couldn't hazard a guess at what worldwide usage looks like. I'm surprised every time I hear about the creative ways that countries I would least expect to be heavy cell phone users are using cheap cells for things like currency exchange (http://www.cnbc.com/2013/11/11/cashless-africa-kenyas-smash-success-with-mobile-money.html http://www.cnbc.com/2013/11/11/cashless-africa-kenyas-smash-...).