musicsweep said:You'd probably have said the same thing about FM in 1968. Sure... it has better sound quality, but the signal doesn't travel as far and most car radios don't even have FM receivers...
One of the real benefits full signal FMs had in the 60's was a signal advantage. While most metros had outgrown all or most of their AMs with the urban sprawl of the 50's, FMs (what were later B's and C's) with "full power and tower" vastly outcovered those AMs.
Using today's market definitions (Arbitron MSA's), there are only about 160 AMs in the entire top 100 markets that fully cover (80% of population) their markets with a usable signal, day and night. Yet there are well over 1200 FMs that do that.
At the beginning of 1967, the FCC made FMs stop simulcasting AM sister stations. This forced many new formats on the "vacated" band. While there were very, very few profitable FMs prior to '67 (and thus the FCC's action) the band rapidly became popular and receivers came way down in price. Since most radio listening was not (and is not) done in the car, FM could quickly take audience away from commercially heavy, talky and stodgy AMs. And in many parts of the major markets, they were used even more since AM options were few, particularly at night.