https://norvig.com/norvigs-law.html

                            Norvig's Law

We all know about Moore's and Gilder's laws, that CPU power and
bandwidth will double every 18 and 6 months, respectively. Less
familiar are the more pessimistic laws, such as Proebsting's law,
which states that compiler research has led to a doubling in
computing power every 18 years.

In July 1999, there was a news article stating that PC usage had
doubled yet again, reaching penetration of 50% of homes. People were
hailing this as yet another sign of the inevitable climb of
technology, but I saw it as a warning sign that the glass was half
empty, and coined the following:

          +-----------------------------------------------+
          |                 Norvig's Law                  |
          |                                               |
          | Any technology that surpasses 50% penetration |
          |            will never double again            |
          |          (in any number of months).           |
          +-----------------------------------------------+

To be clear, it all depends on what you count. If you're counting
units sold, you can double your count by selling everyone 1 unit,
then 2, then 4, etc. (In Finland I understand that cell phone usage
is above 1 per capita, but still growing.) If you're counting the
total number of households that own the product, you can double your
count by doubling the population, or by convincing everyone to
divorce and become two households. But if you're counting percentage
of people (or households), there's just no more doubling after you
pass 50%.

So the next time you hear about the doubling of another technology,
remember you heard it here first.

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Peter Norvig