I think many of your examples are wrong. Time magazine, Warner Bros, TBS and HBO all benefitted immensely from excellent products and word of mouth. Regarding

I think many of your examples are wrong. Time magazine, Warner Bros, TBS and HBO all benefitted immensely from excellent products and word of mouth. Regarding Comcast, I know you're hung up on the use of "only" but being a government-issued monopoly probably makes it a less interesting example for this topic. Despite that, we would need to go back in Comcast's history to really understand how it grew. Oracle and Cisco are terrible examples since they originally produced market-leading products and gained very strong word-of-mouth. From a cursory reading of Epic history, it also sounds like a bad example for you since it relied heavily on reference customers. Drugs obviously have huge word-of-mouth spread.