I keep getting email from people that says:
"I don't get it. Please explain this joke to me."
Kinda takes the fun out of it, but if you really don't "get it", here you go:
"No soap. Radio." is classic anti-humor.
It has all of the telltale signs of a typical joke:
But in reality, it's simply not funny. There's nothing to "get".
And that's what's funny.
The humor is a result of the cognitive disonnance caused by a violation of the expectation that it was a joke and therefore should be funny.
It works best in a social setting with a group of people who are in on the
joke and a single person who has never heard it before. One person tells
the "joke" and the rest of the group laughs/snickers/groans. This emphasizes
the expectation that the joke should be funny, leaving the poor soul
who's not in on it an unenviable choice: Either risk looking foolish by
saying "I don't get it", or try to pretend they find it funny and laugh
along with the rest of the group.
The most classic piece of anti-humor you're probably already familiar with.
Q: Why did the chicken cross the road?
A: To get to the other side.
Other similar jokes cross the line from anti-humor to meta-humor.
Q: How many surrealists does it take to screw in a lightbulb?
"Fish" isn't a punchline, per se, as it has nothing to do with the question. However, the form of the non-punchline is (arguably) surreal. So, the seemingly unrelated punchline is resolved, but only by forcing the listener to cross meta-levels (which causes the kind of unexpected congnitive dissonance we percieve as humor).