A commercial as seen on Paris and Torres' TV set
Tribbles Cereal Commerical "...Tribbles."
A commercial was a promotional medium used in television or radio to sell products or services, subsidizing the programming the audience was enjoying.
A commercial was once made advertising a number of different kinds of "Tribbles" cereals, though the context in which the commercial was made is uncertain. (ST: "The Trouble with Edward")
Paid commercials were used by Empire TV on planet 892-IV in 2268, broadcast during highly popular programs such as Name the Winner. (TOS: "Bread and Circuses")
Bang Bang Automatic Rifles advertised its products on a radio station on Sigma Iotia II in the same year. (TOS: "A Piece of the Action")
A real estate commercial falsely advertised property on "beautiful Nimbus III" in 2287. (Star Trek V: The Final Frontier)
When B'Elanna Torres recreated a TV set for Tom Paris in 2376, she didn't understand the purpose of a jingle, a song designed to add appeal to a commercial. (VOY: "Memorial")