From an article in MIT's Technology Review "Are Smart Phones Spreading Faster than Any Technology in Human History?":
"Presented in the top graphic above is the U.S. market penetration achieved by nine technologies since 1876, the year Alexander Graham Bell patented the telephone. Penetration rates have been organized to show three phases of a technology's spread: traction, maturity, and saturation.
Those technologies with "last mile" problems—bringing electricity cables or telephone wire to individual homes—appear to spread more slowly. It took almost a century for landline phones to reach saturation, or the point at which new demand falls off. Mobile phones, by contrast, achieved saturation in just 20 years. Smart phones are on track to halve that rate yet again, and tablets could move still faster, setting consecutive records for speed to market saturation in the United States.
It is difficult to conclude categorically from the available data that smart phones are spreading faster than any previous technology. Statistics are not always available globally, and not every technology is easily tracked. Also, because smart phones have not yet reached market saturation, as electricity and television have, the results are still coming in.
Smart phones, after a relatively fast start, have also outpaced nearly any comparable technology in the leap to mainstream use. It took landline telephones about 45 years to get from 5 percent to 50 percent penetration among U.S. households, and mobile phones took around seven years to reach a similar proportion of consumers. Smart phones have gone from 5 percent to 40 percent in about four years, despite a recession. In the comparison shown, the only technology that moved as quickly to the U.S. mainstream was television between 1950 and 1953."
MP: How does this fit in with "The Great Stagnation" hypothesis?