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[[caption-width-right:300: One is about how society (or lack thereof) functioned in a time long past, and how it shaped our world today. [[BaitAndSwitchComparison The other is about dinosaurs.]]]]

->''"You asked for it, you got it! An entire 48-hour marathon of ''Ghost Harassers'' on the Used to Be About History Channel!"''
-->-- ''WesternAnimation/GravityFalls'', "Northwestern Mansion Mystery"

Many cable channels are created to fulfill [[NicheNetwork a specific programming niche]], and their name is ExactlyWhatItSaysOnTheTin ó the Golf Channel shows golf, the [[Creator/{{GSN}} Game Show Network]] shows {{Game Show}}s, and so on.

Some channels, however, are not as wedded to their original concept as others. [[ExecutiveMeddling Meddling executives]] look at the {{demographics}} to whom their channel appeals and decide that, hey, since the people watching their SpeculativeFiction [[Creator/{{Syfy}} channel]] are mostly 18-31 males, and ProfessionalWrestling is hot among that demographic, surely no one would mind if they started showing pro-wrestling!

The fans of the original programming ''will'' mind, of course, but the channel tends to keep going regardless. This may show up with only a couple of odd programs in the schedule, but far too often, given enough time, a channel will have pretty much abandoned its original concept. Whether or not the former invariably leads to the latter is a subject for debate.

Since the network is strongly impacted by the ratings, and the highest ratings go to generally the same few demographics, this tends to lead to networks becoming [[FollowTheLeader more and more like each other]], either in similar programming or outright airing the same shows.

Some changes can be chalked up to the changing landscape of TV. As the number of channels goes up, networks re-align themselves to try and hold some of their market. That, or the parent companies who might own seven or more cable channels each shuffle stuff for "synergy" or to reduce redundancy. Competition with new media is prevalent as well -- classic reruns give way to DVD box sets (and the ''real'' killer, {{Creator/Netflix}} and similar streaming services), music-video channels give way to Website/YouTube and iPods, and info-dumping all-text channels give way to the data display in a digital cable box, smartphone apps (once again, the ''real'' killer) or some new-fangled webernet site. Other times, it's just shifting to whatever the network feels will attract the biggest audience -- [[MoneyDearBoy and the audience that lets them charge the most for ads]] (especially the lucrative young adult demographic, needless to say).

Depending on the network and how the decay is carried out, [[TropesAreTools changing concepts can be either good or bad for the channel]]. If the Network Decay works out, it may expose the channel to thousands, if not millions of new viewers, who would normally never watch the network in the first place. Or perhaps the earlier direction just was not working out and the network made changes in order to get better and more profitable programming. Furthermore, there are several good shows floating around in DevelopmentHell that wouldn't stand a chance of getting picked up unless a network decides to spread its wings. If the decay doesn't work out, however, then it can create a BrokenBase among the channel's viewers, and can throw the network into a DorkAge. Even ''if'' the decay works, the expanded viewership would come for naught for the various programs now squeezed out of the network's scheduling - once again, pointing out that good and bad can come of it, depending on the viewer.

Also called a [[https://en.wikipedia.org/wiki/Channel_drift Channel Drift]] on Wiki/ThatOtherWiki.

See MagazineDecay for the print equivalent. See also ArtifactTitle, TheyChangedItNowItSucks, ScrewedByTheNetwork, and AdoredByTheNetwork. PublicMediumIgnorance may be a cause for some of the listed networks. If the network decays so much that it's renamed to fit the new focus, then the older network no longer exists and it's a case of {{Network Death}}. If it starts overlapping with politics, then it can cross over into StrawmanNewsMedia.


* NetworkDecay/InfluencesOnOtherMedia \\
Instances of this phenomenon when it comes to related mediums (Radio, Magazines, Websites, etc).
** MagazineDecay has its own page.
* NetworkDecay/InUniverseExamples \\
InUniverse [[BitingTheHandHumor lampshades and mockeries of this phenomenon.]] Also, fictional networks.
* NetworkDecay/MajorShiftsThatFit \\
The channel has been pushing or narrowing the limits on what they can show without leaving their genre entirely and/or are being too over reliant on a CashCowFranchise or two, but at least what they are doing still fits the original mission somewhat.
* NetworkDecay/NotableAversions \\
The channel has managed to avoid decay, either by working on a genre that is broad enough that it is unnecessary to decay, or that the executives feel that channel is good enough that they donít need to. Of course obviously any channel that is not listed on this page would count as this, but weíve listed a few (honorable) mentions.
* NetworkDecay/{{Slipped}} \\
The channel still shows programming related to its original concept, although it is significantly showing programming not related to their genre in some way.
* NetworkDecay/TemporaryShifts \\
The channel, after decaying for a while, has since returned to its roots and are showing programming related to their original mission again.
* NetworkDecay/TotalAbandonment \\
The channel, with the exception of perhaps a few shows, has long abandoned its original concept.
* NetworkDecay/UniqueSituations \\
The channelís decay either is in a situation where it doesnít fit any of the other categories, or is constantly fluctuating between decaying and recovering.

-->''Say, wasn't Wiki/TVTropes only about television before? Hell, doesn't ANYONE talk about idioms in here anymore?!''