In early 1927, the New Yorker begins mentioning a revolutionary telephone that everybody wants to have. Called "The French Phone," I didn't know what the heck it was until I ran across this cartoon this morning:
It seems this type of phone -- with the receiver and headset combined into one section, the way we know it today -- cost more to install and caused minor havoc with the Bell Telephone company.
To get around the higher cost, people bought cheaper French Phones made by third-party companies and installed them personally. But Bell had a contract in its clause that nobody had paid attention to previously: you were not allowed to use non-Bell accessories with Bell's telephone service.
From the sounds of it, this prohibition was pretty much unenforcable. It may have begun the breakdown of Bell's phone-and-service monopoly. If you're interested in learning more about early telephones, check out this site. But I warn you: you'll suffer a disturbing MIDI loop of "Puttin' On the Ritz."
PS: Why was it called "The French Phone?" Apparently it resembled phones in Europe. What that means exactly I'm not sure.