“The greatest thing since radio”

Radio was regarded as a great invention in the early 1900s, and other wonders were hyped as “the greatest thing since radio.” The expression “greatest thing since radio” has been cited in print since at least 1935.
 
“The greatest thing since sliced bread” is a similar expression that became popular in 1951.
   
 
14 January 1935, Des Moines (IA) Register,  “More Laurels for Wirephoto,” pg. 11, col. 1:
“Greatest thing since radio.”
 
2 November 1938, Boston (MA) Globe, pg. 26, col. 6 classified ad:
The mechanical specialty we are putting on the market has been called the “Greatest thing since Radio.”
 
14 May 1939, Boston (MA) Herald, pg. 21, col. 4 classified ad:
This equipment manufactured by an American company is an American invention. It has been called the greatest thing since Radio.
 
3 July 1939, Medford (OR) Mail Tribune, “Side Glances” by Tribune Reporters, pg. 1, col. 1:
Roland Halper thinking his new Chrysler car just about the best thing since radio.
 
4 August 1939, Middletown (NY) Times Herald, pg. 13, col. 3 classified ad:
MEN to introduce: The greatest thing since Radio in this territory.
 
1 February 1942, The Idaho Sunday Statesman (Boise, ID), pg. 5, col. 4 ad:
GREATEST THING SINCE RADIO!
REXAIRE
-CLEANER
-AIR CONDITIONER
-HUMIDIFIER
 
Google Books
The Children’s Hour
Edited by Marjorie Barrows
Chicago, IL: Spencer Press
1954
Pg. 4:
When Dr. Haley described his earth-stirring invention, the auditorium burst into an outspoken mixture of reactions: “A time machine! Fantastic!” “Entirely fictional!” “This is the greatest thing since radio!”
 
Old Fulton NY Post Cards
31 May 1983, Daily Sentinel (Rome, NY), pg. 4, col. 2 ad:
GREATEST THING SINCE RADIO
RACING AT VERNON DOWNS
 
27 January 1994, The Globe and Mail (Toronto, ON), “Collected Wisdom,” pg. A17, col. 4:
The answers: Thomas E. Reid of Oakville, Ont., says he hates to admit that he’s old enough to remember, but before the days of sliced bread people used to say “the greatest thing since radio.” Mike Pearce of Collingwood, Ont., says the greatest thing before sliced bread was unsliced bread. But CW’s favourite reply comes from Bob Rogers of Etobicoke, Ont., who thinks the greatest thing before sliced bread was undoubtedly the mechanical bread slicer.
 
Twitter
Matt Holt Comedy
‏@holtcomedy
@chickmcgee1 the best thing since radio shows about sliced bread
7:22 AM - 2 Jul 2012