“Auction—where you get something for nodding”—a pun on “nothing”—was published in a newspaper in January 1956. “Daffynishion: Auction — Where you get something for nodding” was published in Boys’ Life magazine in August 1956.
   
The “something for nodding” auction joke has been included in several books.
   
       
12 January 1956, Marengo (IL) Republican-News, “Jokes?,” pg. 15, col. 3:   
Auction—where you get something for nodding.
 
Google Books
August 1956, Boys’ Life, “Think and Grin,” pg. 64, col. 4:
Daffynishion: Auction — Where you get something for nodding. — Duane Selke, Wausau, Wis
 
8 March 1957, Pittsburgh (PA) Post-Gazette, “It Happened Last Night” by Earl Wilson, Magazine, pg. 31, col. 4:
EARL’S PEARLS
An auction, says Martha Scott, is a place where, if you’re not careful, you’ll get something for nodding.
   
Google Books
Braude’s Handbook of Humor for All Occasions
By Jacob Morton Braude
Englewood Cliffs, NJ: Prentice-Hall
1958
Pg. 256:
Auction: a place where, if you aren’t careful, you’ll get something for nodding.
 
13 January 1962, Chicago (IL) Daily Tribune, “A Line O’ Type Or Two,” pt. 1, pg. 8, col. 3:
An auction is a place where you get something for nodding. (...) Quin Ryan
 
7 May 1962, Hartford (CT) Courant, “Today’s Chuckle,” pg. 1, col. 1:
An action is where if you’re not careful, you’ll get something for nodding.
   
Google Books
September 1980, Boys’ Life, “Think & Grin,” pg. 81, col. 1:
Daffynishion: Auction — A place where you get something for nodding.—Todd Kemp, Clovis, Calif.
   
Google Books
Wit in English
By Paul Joel Freeman
Xlibris Corporation (Xlibris.com)
2009
Pg. 126:
An auction is where you get something for nodding.
 
Twitter
George Johnson‏
@LadyKentmores
Auctions; still the one place where you can get something for nodding
3:56 PM - 13 Jul 2012
 
Twitter
Alderfer Auction‏
@AlderferAuction
Everyone knows #auctions speak louder than words - that’s because of the auction-ears…it’s the one place you can get something for nodding
2:44 PM - 6 May 2014
 
Twitter
Benjamin Ranyard‏
@higgledygarden
I love auctions….I always get something for nodding.
12:49 PM - 9 Jan 2015
 
Twitter
Sackrider Auctions‏
@GordySackrider
Auctions are the one place where you can get something for nodding.
Though, you do have to stay ‘til the bidder end.
#AuctionJokes
3:01 PM - 4 Feb 2016
 
Facebook
The Hoop Group Auctions - Amarillo added 4 new photos.
January 3, 2017 ·
What does an auctioneer have to know? LOTS!
HAHAHA
How do they learn about all the lots? By using their AUCTION-EARS!
HAHAHA
Auctions are the one place you can get something for nodding….
HAHAHA