Mars used the slogan for more than 35 years, but it last appeared in the brand's television ads in 1995, and, in 2002, it was even dropped from Mars' packaging as part of a redesign.
Mars believed that the Mars bar had a customer base that was too male, when women make up most of the confectionery market, and so they replaced the old slogan with the supposedly more female-friendly "pleasure you can't measure".
It would be something of an understatement to say the new slogan never lodged in the public's consciousness in quite the same way as the original. So, after a six-year break, Mars has brought back the old favourite.
The new ad is set in the austere surroundings of a monastery, with a group of monks ringing the church bells.
After tucking into some Mars bars and exchanging a few conspiratorial glances, they start ringing the bells to House of Pain's Jump Around, leaping high into the air and hanging off the rope-pulls. The ad then ends with the familiar "work, rest, play" slogan, albeit appropriately pruned to give what Mars hopes is a more contemporary feel.
Figures on BrandIndex show that Mars' brand image has improved since the ad first aired on 2 March. The brand's customer satisfaction rating is up three to +33, and its recommend to a friend score, which acts as a proxy for whether people are likely to go and buy a product themselves, has risen four points to +23.
On the basis of these figures, it seems as though Mars is showing a return to form.
YouGov interviews 2,000 people each weekday to form its BrandIndex, a daily measure of public perception of more than 1,100 consumer brands across 32 sectors.
It is measured on a seven-point profile:
2. General impression
7. Corporate reputation
In addition, we supply an index score.