Adoption Curves and Liver

I have a very interesting chart of technology adoption during the last century. It was originally produced by the Wall Street Journal, but I have a small copy reproduced in the book Rules for Revolutionaries by Guy Kawasaki (Harper, 1999). The chart shows, for a variety of technologies from the telephone to satellite TV, the growth of each in the marketplace as a function of year. The Y axis is expressed in percentage of (U.S.) households, so none of the curves exceeds 100%. Generally all of the curves follow an S-shape, that looks like exponential growth at first, but then eventually levels off as the technology saturates the marketplace.