[i]In logic and critical thinking, a slippery slope is a logical device in which a person asserts that some event must inevitably follow from another without any rational argument or demonstrable mechanism for the inevitability of the event in question. A slippery slope argument states that a relatively small first step leads to a chain of related events culminating in some significant effect, much like an object given a small push over the edge of a slope sliding all the way to the bottom. This type of argument is sometimes used as a form of fear mongering, in which the probable consequences of a given action are exaggerated in an attempt to scare the audience. [/i]
Slippery slopes are also based on observation.
Rival company buys some stock but says they aren't buying the whole company. Then a few years later they buy the whole company.
Company let's employees dress business casual on Fridays. Then Friday becomes jeans day. Then employees go business casual everyday. [spoiler]this kind of slippery slope is awesome[/spoiler]
Call of Duty sells gun skins. Then they sell requisition packs. Then they sell requisition packs with the best gun in the game.
The slippery slope is not a fantasy concocted by crack pots. It happens . . . [spoiler]if you let it.[/spoiler]