That was in the 1960s and this guideline in particular was set by Richard Prentice Ettinger, founder of the world's largest publisher Prentice-Hall (now a part of the Pearson Group, UK), for copywriters working for his company.
But today advertisers are increasingly replacing sex appeal with humour as the way to reach the consumer's purse.
A look at the Indian advertising scenario now shows that an overwhelming number of TV commercials rely on being funny, irrespective of whether the product is low involvement, such as soft drinks, beer or candies.
"Humour can work anywhere. There are no rules, " said Arvind Bugga, chief strategist with Delhi-based advertising agency K Factor.
"We had created an ad for Lakshmi Cement. To emphasise the strength of the cement the visual clip showed a cyclist with bags of Lakshmi Cement colliding with a truck. The truck disintegrates but the cyclist with his cement remains intact.
Cement is a high involvement product and yet the humour worked. Our client ran the ad for more than two years, " Bugga told.
The rules of the game have changed, especially for TV commercials. While print media ads are still rather staid, most audio-visual advertising, whether here in India or in more developed markets such as the US, relies heavily on humour to attract attention.
"Humour is the new sex in advertising, " says Mokokoma Mokhonoana, founder and creative director of South African ad agency Two Way and author of Design Literacy Journal.
Marketing pundits have for long believed that humour is best used for products that are low involvement, low cost and purchased regularly.
"In fact, this has been established empirically by something known as the Product Colour Matrix, " Anindya Chatterjee, professor of marketing, Slippery Rock University, Pennsylvania, told.
But Indian advertisers are certainly challenging the wisdom that humour works only for certain categories.
Humour is being used even for high involvement products like insurance or pension funds such as the Max New York Life ads where a child is asked to pronounce "Czechoslovakia" or where a retired man is planning to go to a distant city to attend the marriage of the daughter of someone whom he hardly knows.
The comic element can be found in many other high involvement products such as mobile phone services (Vodafone), motor cars (Hyundai Santro), television sets (Sony Bravia), and motor bikes (Hero Honda).
"Today with so many people suffering from depression and suppressed anxiety, humour brings relief and catches
attention, " said Bashab Sarkar, MD and CEO of Delhi-based advertising agency Media Pros.
"There are two major routes to catching attention - testimonials and humour. But the main thing is big ideas are missing and there are too many products.
So, often there is no choice but to use humour, " Sarkar told.
Of course, there are downsides. "There is certainly a big risk when using the comic element. It has to be executed perfectly just as a joke has to be told perfectly - otherwise it falls flat and no one laughs, " Bugga said.
"Relevance is another key element, " said Sarkar. "The Vodafone campaign with little white characters is funny but it is done in such a way that all the attributes that Vodafone wants to highlight are brought to the viewer's attention, " he said.
Some marketing gurus are, however, downright sceptical of using humour in advertising.
"Even if people find your humour amusing, does it sell? My belief is that generally it does not. What sells are clear benefits, " says Michael Hepworth, a top marketing consultant in the US and whose free "Marketing Tips" magazine is read by thousands of business owners around the world in more than 47 countries.
I would certainly advise against indiscriminate use of humour, " said Chatterjee.
Even as the marketing gurus slug it out over the issue of using humour in advertising, the creative honchos in ad agencies are merrily going ahead with laugh riots.