I believe there's a relation between handset price and advanced use. People with cheapo smartphones often don't even realize that they can send emails, browse the web, and use apps with their phone. The vast majority of Nexus S and iPhone owners use at least some of the smartphone features that their device offers.

I mention this because I think GP was talking about people using smartphones, not simply owning one. I know plenty of folks who own Nokia and LG smartphones but have never downloaded an app, visited a website on their phone, or synced their phone to a computer.