Horace Dediu:

The decision making process for buying computers, which began with large companies IT departments making decisions with multi-year horizons, has changed to billions of individuals making decisions with no horizons. Companies have become the laggards and individuals the early adopters of technology.

The fundamental shift is therefore in the quantity of decision makers and the quality of those decisions. Those who buy are also those who use and their decisions will be perhaps whimsical, maybe impulsive and not calculated, but fundamentally, in the aggregate, wise.