Cliff Effect – (May be known as All-or-nothing-effect) - This is a euphemism in regard to how digital TV reception can change so dramatically with a comparatively small amount of poor reception. When experiencing less than desirable reception, typically the picture of an analog television becomes snowy, blurry and/or wavy.  With DTV, a comparably weak signal causes the DTV picture to change from a perfect picture to nothing (thus the all or nothing scenario.)

See the Interactive Television Institute.