Whereas it took electrification 45 years to reach 90% of US residents, it’s taken only 20 years for cell phones to reach the same penetration. The rate of diffusion is accelerating. A straight line extrapolation would suggest that the rate of technological adoption should continue to accelerate until it occurs instantaneously. By the year 2100, a personal teleporter, say, should be adopted by everyone alive the year it is introduced. A new immersive VR suit the day after it is released. And a new wireless wearable communicator the hour after it is invented. However that scenario is unlikely to happen because technology specializes as fast as it becomes common, so most technology will not be adopted by most people. In fact the more complex the technology, the less likely it will reach near-ubiquity. The peak global penetration for the average technological innovation will drop over time. We can see a hint of that in the chart above. The level of peak penetration at which diffusion plateaus is falling over time. Any particular new species of communication device in the next century is unlikely to every reach the same ubiquity as machine-woven cotton cloth, or even the television.