Coke is so proud of the 1971 ad that featured in 'Mad Men' last night it has been revived again and again over the years
And so, after eight years, we say farewell to AMC's "Mad Men."
And what better tribute to the industry in last night's finale than to end on one of the most iconic campaigns in history: Coca-Cola's 1971 "Hilltop" campaign - with the famous "I'd like to buy the world a Coke" song.
McCann Erickson advertising executive Bill Backer came up with the original concept for the ad when flying to London. Heavy fog in London forced the place to divert to Shannon in Ireland. Some passengers were furious with the accommodation they were made to stay in. But by the next day, after having a shared experience, Backer saw them laughing and joking over snacks and bottles of Coca-Cola.
Backer said of the idea: "So that was the basic idea: to see Coke not as it was originally designed to be - a liquid refresher - but as a tiny bit of commonality between all peoples, a universally liked formula that would help to keep them company for a few minutes."
So popular was the idea that the campaign has been repeated - sometimes in different forms - several times over the years.
We've taken a look back at the many iterations of "I'd like to buy the world a Coke."
Mid 1970s
Coke first revived the campaign just a couple of years after it first aired in 1971. The re-working of the ad showed a group of people at night, holding white candles and ended on the tagline "Seasons greetings from your bottler of Coca-Cola."
A festive version of the jingle was used for many years as Coke's annual holiday commercial.
1990 Super Bowl
After a long hiatus, the famous tune returned for the big game. The ad featured the original singers - now adults, obviously - and their children. The ad then turned into a medley, featuring the brand's then-jingle "Can't Beat the Real Thing."
2005 Coke Zero
Blending old and new, Coke re-made the "I'd like to buy the world a Coke" once again in 2005 to launch its new no-sugar variant Coke Zero. Artists G Love and Special Sauce re-wrote the lyrics to "I'd like to teach the world to chill."
2006 Singapore
Advertising industry trade magazine reported that Coke Singapore restored the "Hilltop" ad to a high definition format on its 35th anniversary. It was added to a 20,000-piece collection of Coca-Cola ads in the Library of Congress.
2011 Coke's 125th anniversary campaign
The legendary tune returned once again in 2011 to mark the brand's 125th anniversary.This time the song wasn't tampered with, but the footage was peppered with images from over the ages such as World War II ending in 1945 and revelers celebrating the turn of the millennium.
2012 Google's Project Re:Brief
Winner of the coveted Cannes Lions Grand Prix prize the following year, Google partnered with four global brands including Coke to reimagine famous ads for the mobile era. The new ad allowed people to actually "buy the world a Coke" using Google's display advertising platform and a series of specially-made vending machines. People could record a message and send it with a can of Coca-Cola, connecting them with someone at a vending machine on the other side of the world. Recipients could also send a video or a text of thanks back.
2015 "Mad Men"
The ad returned to screens once again during the final ever episode of "Mad Men" on May 17. Adweek reported that Coca-Cola knew it would be in the finale, but that was about all it knew. In the episode, Don Draper came up with the idea after being inspired by a meditation retreat.
McCann, the agency behind the original spot, tweeted: