What was a silly millymeter longer?

In 1967, Liggett & Myers introduced a 101mm long cigarette, Chesterfield 101s. They were 1mm longer than two recently-introduced 100mm cigarettes, and were advertised with a campaign that emphasized that they were "a silly millimeter longer". That is 39/1000 of an inch!

I found no matches for 'silly millymeter'. This story from 'Time' magazine has the title "Silly Milly".

http://content.time.com/time/subscriber/article/0,33009,902151,00.html

In 1968, William Weege produced a silkscreen print in colors with photo effect, 17 1/2" x 24" (to quote the auction catalogue) called 'A Silly Milly Meter Longer.'

http://www.liveauctioneers.com/item/2867363