The name and taste derived from a then-popular malted milk drink (milkshake) of the day, not after the astronomical galaxy.

[8] In 1935, Mars used the marketing slogan "The sweet you can eat between meals,"[6] later using "At work, rest and play, you get three great tastes in a Milky Way."

The campaign portrayed the comical aftermath of what happens after someone (off camera) is distracted due to eating a Milky Way bar.

Because of this low density (0.88 g/cm3), it floats in milk, an attribute highlighted in an advertising campaign in several European countries.

[14] In the UK, Mars introduced the Flyte bar, which was identical to the old-style chocolate flavored Milky Way, marketed in twin packs and discontinued in 2015.

Subsequently, reference to the characters was dropped, the packaging since depicting blank stars, although the faces remain in the chocolates themselves.

A long-running advertising slogan for the product in the United Kingdom and Australia was, "The sweet you can eat between meals without ruining your appetite".

[15] In 1991, the Health Education Authority and anti-sugar lobbyists both complained, without success, to the Independent Television Commission that such advertising encouraged children to eat sweets between meals.