The key attribute of small tablets that will drive them into mainstream use is low cost. But the implications of why that will prove to be the case are underappreciated as a driver of massive adoption.

How low will they go? I think that over the next two years, the "sweet spot" range for 7-inch tablets is between $100 and $200.

Sure, we've seen lots of phones at these prices and below. But phones require wireless service, which brings the total cost of ownership into the many hundreds or thousands of dollars for the life of the device.

With small tablets, consumers will pay one very low price -- and they're done spending.

Wi-Fi is becoming far more ubiquitous now because people are using personal hotspots -- features that let several Wi-Fi connections piggyback onto a mobile broadband connection.