Earlier quoted context omitted.
I'm an almost 25-year veteran of the cable industry and I can tell you that Comcast and Time-Warner didn't grow huge via word-of-mouth. The benefits of cable service grew community systems by word-of-mouth, then Comcast and Time-Warner grew by acquiring and consolidating systems. For example, Time Warner Cable Oceania now provides cable service to the entire Hawai'ian island chain, but they had just bought out the la…
Most of the companies you mention are not counterexamples, because they were already big when they started acquiring and merging with other companies.
Iirc (this was a long long time ago) his Philadelphia connection to Ralph Roberts (comcast) was how he built Jerrold (they made cable boxes).
Comcast of course grew large by starting and getting it's first cable franchise in a small town in Mississippi. Nobody chooses their cable company the cable company chooses you.
(I actually have an audio tape of that interview that I made.)