Diffusion of Innovations

How is it that some technological innovations get taken up by the masses, and others don’t? How important are innovators and early adopters in this?
Well Mr. Rogers apparently wrote the bible on this:

Rogers, E.M. (1995). Diffusion of innovations (4th edition). The Free Press. New
York.

Here’s the theory laid out in bare bones with an applied example

Here’s a point by point precis
http://www.ksu.edu/humec/atid/UDF/diffusion_model.htm
and here’s a precis of the theory.