Nike, Inc., an athletic apparel company, posted a billboard in Atlanta at the time of the 1996 Summer Olympics:
 
“You Don’t Win Silver — You Lose Gold.”
 
The advertisement was controversial by calling someone who wins a silver medal (and is the second best in the entire world) a “loser.” The sports saying is still often referred to by coaches, athletic participants and fans, even by those with no recollection of the original 1996 Nike ad.
 
Similar sports sayings include “First is first and second is last” and “Second place is the first loser.”

 
Wikipedia: Nike timeline
1996
. Nike causes controversy with its advertising campaign during the Summer Olympics in Atlanta which features the slogan, “You Don’t Win Silver — You Lose Gold.” Nike’s use of this slogan draws harsh criticism from many sources, including - not surprisingly - several former Olympic silver and bronze medalists.

Google News Archive
4 August 1996, The Sunday Argus-Press (Owosso, MI), “Hornus’ Hunches” by Tony Hornus, pg. A5, col. 1:
What’s the slogan by Nike, “You don’t win the silver, you lose the gold.”
 
4 August 1996, Rocky Mountain News (Denver, CO), “The medals are precious, even if the metals aren’t” by Bob Kravitz:
Her sponsors at Nike say, “You don’t win silver, you lose gold.”
 
Google Books
The Bad Attitude Survival Guide:
Essential tools for managers
By Harry Chambers
Reading, MA: Addison-Wesley
1998
Pg. 44:
The dichotomy of winning versus not winning is very destructive. Perhaps a good example of this is the advertisement run by the Nike Corporation at the conclusion of the 1996 Olympic Games in Atlanta proclaiming: “You don’t win Silver, you lose Gold.” The message clearly was “If you are not the best performer in your selected event, you are a loser.” Given this mentality, we must be a planet of losers! How many people can ever say they arethe very bestat what they do? Those who are number two or below, must relegate themselves to the distasteful designation of “loser.” This distortion of winning not only feeds resentment, it spawns a win-at-all-costs mentality—rules, honor, ethics, and morals be damned. The ends justify the means. Winning covers all sins, and there can be only one winner. Focusing on success versus winning is a much healthier pursuit.
 
New York (NY) Times
THE MEDIA BUSINESS: ADVERTISING—Fighting Marketing Pirates; Sponsors Guard Their Investments at Olympics
By MARK LANDLER
Published: September 29, 2000
(...)
For all the talk, Nike seems to have mellowed. Four years ago, it thumbed its nose at the whole concept of sponsorship. ‘‘We don’t sell dreams. We sell shoes,’’ declared an eight-page advertising insert in Sports Illustrated. A television commercial said: ‘‘You don’t win silver. You lose gold.’‘
   
USA Today
Silver medal a reminder of how close he was to gold
By Megan Finnerty, The Republic | azcentral.com
Posted 7/20/2012 04:20:14 AM
The big black and white Nike billboard at the Atlanta Olympics was supposed to be inspiring: “You don’t win silver. You lose gold.”
 
But when Ahwatukee Foothills’ Townsend Saunders read it, moments after walking out of an arena wearing a silver medal, those words stung.
 
“It’s not terrible for everyone else to read; it’s just terrible for all the silver medalists,” he said 16 years later.
 
At the 1996 Games, Saunders, then 29, took the silver medal in men’s freestyle wrestling.