24/7 is commonly an abbreviation of the phrase
"24 hours a day, 7 days a week", which, about
30 years ago, was a clever way for advertisers to say
all the time. Today this phrase
has become some of the hackneyed tripe spewed forth
by the ubiquitous marketers of our so-called culture.
In a vain but slightly amusing attempt to kill the use
of acronyms and shortcuts in everyday speech,
I enjoy mutilating such abbreviations. For example,
FRIEND: So Miles D., did you find Yahoo's customer service
MILES_D: Oh yeah, they're available 24/7:
24 hours a week, 7 weeks a year.