The following is a quote from Walter Elmore, a recently deceased power systems protection engineer:
Edison was a brilliant inventor despite the fact that he had little formal education and lived in New Jersey. His first invention in 1877 was the phonograph which could soon be found in thousands of American homes where, as Dave Barry pointed out, it basically just sat until 1923 when the record was invented. But Edison's greatest achievement came in 1879 when he invented the electric company. Edison's design was a brilliant adaption of the simple electric circuit. The electric company sends electricity through a wire to a customer, then immediately gets the electricity back through another wire. Then (this is the brilliant part) sends it right back to the customer again.
This means that an electric company can sell the same batch of electricity thousands of times a day and never get caught, since very few customers take the time to examine their electricity very closely. In fact the last year in which any new electricity was generated was 1937. The electric Companies have been merely re-selling it ever since, which is why they have so much free time for studying rate increases.
(From his keynote address given in May 1997 To IEEE/PSRC Williamsburg, VA, as transcribed by PAC World Magazine.)