A simple Show Within a Show gag. With the sheer number of television stations available in this day and age, a channel that only has programming which relates to a single hobby or niche can be viable. Think "The Golf Channel" or "Soapnet" for real life examples of this. Naturally, these niche' networks aren't all that appealing to people who aren't interested in the networks' subject matter. (Because of this, they are susceptible to Network Decay, if their original incarnation is not giving them high enough Ratings to keep up with the cost of staying on the air.) Some shows like to exaggerate how uninteresting these channels are to non-hobbyists. They do this by having a character turn to a channel that only runs programming about an unbelievably inane subject 24 hours a day.
The gag works because the channel is boring in two different ways. Even if you somehow manage to find the boring subject matter intriguing, the channel is implied to be repetitive ("We're all X, all the time" or "X, 24 hours a day.). As if that wasn't enough boredom, some shows add to this gag by having an extremely bored sounding man narrate the channel's programming in a bland monotone.
To put it simply, a show you're watching makes up a TV channel. If the gag works, you'll be asking yourself one question about that channel. "Who would watch that boring crap?"
- One Dilbert strip had a network that consisted entirely of videos of Ratbert slapping himself while singing Barry Manilow songs. And it was apparently not the stupidest channel that cable company had to offer.
- In Back to the Future Part II, the video screens in (then)-Future Marty's house plays the Scenery Channel. Among the chatter that the future McFly's engage in around the breakfast table, the voice of Marty's son can be heard saying something about the Atrocity Channel.
- CSPAN and other networks that focus on Political Programmes are often portrayed this way in kids' shows. As are 24-hour News Broadcast channels.
- Shining Time Station had the kids introduced to television via Schemer, who showed them such channels as footage of babies crying.
- Though not TV networks, the 'guest newspapers' from which Have I Got News for You takes some of its fill-in-blanks headlines for the final round are basically this trope. And they're all real.
- An episode of America's Funniest Home Videos had a segment that parodied niche channels. The channels featured were "Polka Planet", "The Fashion Channel", "Toilet TV", "The Belly Button Network", "The Chiropractor Channel", and "Tin Ear TV".
- You Can't Do That on Television: Lance complains that the program is taking a very long time to come back from commercial, only for his son to tell him that he is watching the all-ad network. It turns out the program he thought he had been watching was actually an add for a toilet bowl cleaner.
- On the Sesame Street segment "Elmo's World", Elmo's TV tunes in to these kinds of channels to teach kids.
- In Jim Henson's pilot for Inner Tube (which would later become The Jim Henson Hour), Kermit hawks the Inner Tube cable system, claiming there's a channel to match one's IQ, income bracket and clothes. Some samples include the Millionaire's Shopping Network and the All-Kitchen Utensil Channel.
- The Jim Henson Hour has many such channels (which Kermit picks programming from), including "The Fashion Doll Channel", "The Guest Star Channel", "The Time Channel" ("all the time all the time!"), "The All-Dog Network", and a channel devoted to talking garbage.
Kermit: A channel devoted to nothing but garbage?
Bean: Welcome to America.
- The Dinosaurs episode "Fran Live" opens with the Sinclairs exploring their various new cable channels. One of the highlights is "The Hat Channel: 24 hours a day of hat news, hat features, and hat happenings." Robbie seems genuinely excited by the prospect of hat news.
- Siblings has "The Pointless Channel".
- Garfield has this as a common gag. The gag also appeared many times in the 1990s animated adaptation, Garfield and Friends. Some examples include "The Potato Channel" (in which a man lists all the different ways to prepare potatoes), "The All Snail Racing Channel", and "The All Lasagna Channel."
- Duckman had "The Lets Talk In Pig Latin Network", "The All Potato Cakes Network", "The Mismatched Buddy Comedy Network", "The Roadkill Identification Network" and "The Skin Disease Network", all in the same episode.
- Johnny Bravo:
- Johnny once caught a glimpse of the "Fish" Network. The channel's content consisted entirely of video recordings of fish swimming. "All fish, 24/7"
- Johnny also once had a bear named "Chronos, The Master of All Time," watch the "Tree Channel" to try and cure his insomnia.
- The House of Mouse short "Hickory Dickory Mickey" had "The Tick-Tock Channel". Sure enough, with Mickey trying to drown out the annoying tick-tock and an annoying clock, guess what the only thing is that the channel plays.
- Johnny Test: "The Nutz Channel. We're all nuts, all the time."
- Sheep in the Big City had "The Watching Paint Dry Channel."
- The Fairly OddParents! features "Teeth TV" "The Clown Channel", and "The Dungeon Channel".
- The Adventures of Jimmy Neutron: Boy Genius: Carl watches The Llama Channel, a channel with nothing but shows about llamas.
- I Am Weasel:
- The Airplane Channel, which is pretty reasonable. (This was the gimmick of the real-life Discovery Wings channel before it became the Military Channel.) At the end of a Wright Brothers documentary, the brothers decide to toast with a root beer float, after which the channel inexplicably becomes the Root Beer Float Channel.
- The same episode also showed glimpses of the Cat Shaving Channel, and the Grandma Channel. The Root Bear Float Channel was where Chicken finally decided to cancel his cable subscription.
- This was a running gag on 101 Dalmatians: The Series. Various channels on the pups' TV set included "The All-Dog Network", "The All-Cat Network", "The Gravy Channel", "The Poultry Channel", "Swine TV", "The All-Fashion Network", and various others.
- In The Powerpuff Girls episode "Daylight Savings" the Professor gives the girls a curfew. The villains take advantage of this and when the Professor tries to watch TV, all the channels he switches to are discussing how Townsville is doomed. He finally finds one that is talking about something else: the time channel. On this channel, Sonny Dial presents the up to the minute time. This reminds the Professor he forgot to set the clocks back, so he can sends the girls back out to save the day.
- From The Simpsons: "Coming up next on The Clock Channel: 6:00."
- Rocko's Modern Life has a 24 hour bagpipe station featuring the "All Scottish Show".
- Daria featured the Pigskin Channel (a decade before the launch of NFL Network) and a fashion channel (which is very reasonable, there are many networks with strong emphasis on fashion).
- The Littlest Pet Shop (2012) episode "To Paris with Zoe" has the TV in the pet shop stuck to the Bread Crust Channel, then the Insect Channel. The latter consists of unaltered footage from a camera left at a landfill.
- The "Kidnapped!" episode of Mike Tyson Mysteries had the Commencement Channel which specializes in commencement ceremonies.
And thanks for tuning into the Commencement Channel. Seriously. We didn't think anybody would ever watch.
- In ReBoot, Mike the TV will sometimes force some bizarre channel upon somebody and is the only one who doesn't find that channel annoying. His favorite appears to be The Commercial Channel, which has no shows—it's entirely commercial time.
- The Critic occasionally went to this well with MJNN, The Michael Jackson News Network ("With bureaus in London, Bangkok, and Disneyland") and The Dryer Channel, which was able to outdraw Jay's show in the ratings. Regarding the latter: "People watch this?" "They don't just watch — they send it money."
- The Puppy Channel.
- In order to give their staff some time off, some networks will play a video of a Yule log burning around Christmastime.
- "That channel that exists to sell knives" aka the Infomercial channel.
- Other examples are available in the Networks article.
- And of course, video hosting services like YouTube or Twitch TV enable the defictionalisation of all the above plus a few that are even weirder, if you like that sort of thing.