:Parkinson's Law of Data: prov. "Data expands to fill the space
available for storage"; buying more memory encourages the use of
more memory-intensive techniques. It has been observed over the
last 10 years that the memory usage of evolving systems tends to
double roughly once every 18 months. Fortunately, memory density
available for constant dollars also tends to double about once
every 12 months (see {Moore's Law}); unfortunately, the laws of
physics guarantee that the latter cannot continue indefinitely.
-- The AI Hackers Dictionary