I want to know the answer to the following question:
What is one area where teleconferencing could not be used?
All the background I'm provided with is that "The greater 1 MHz bandwidth and 6 Mbit/s bit rate of the Picturephone in the 1970s also did not achieve commercial success, mostly due to its high cost, but also due to a lack of network effect —with only a few hundred Picturephones in the world, users had extremely few contacts they could actually call to, and interoperability with other videophone systems would not exist for decades.". Is that enough to answer the question?