One of the more horrifying results of audience testing done since the beginning of Radio broadcasting, Pop jingles represent the subset of melodies with the following properties:

A) They only sound good the first half-dozen times
B) They can strike without warning at the slightest mental stimulus
C) It is impossible to rid your mind of them
D) They can be transmitted by contaminated human hosts
E) Screaming is futile

It can be concluded from these properties that the Pop jingle is really a virus designed by advertisers to infect a larger customer base than would be normally possible.

Particularly popular pop jingles should be treated with caution, as infecting another person via humming or singing is viewed as a social disaster. Unfortunately, that is exactly what motivates sadistic and infection-resistant persons to strike back at their co-workers in an attempt to make themselves feel better (Pissing contest).

Some of the more gruesome pop jingles:

Feliz Navidad
The Roto-rooter commercial
Any Coca-cola song

Michael Jackson songs, while dangerous and infectious, are not considered jingles. They are considered deadly weapons.