What term relates to the impact of an advertisement fading away after a few weeks?

Answer: The term that relates to the impact of advertisement fading away after fee weeks is known is the 'Ad Decay'

Explanation:

Ad Decay refers to the fading away of memories of an advertisement and also little or no continued response to it. Since people claim that nothing is ever forgotten, the term Ad Decay may be more adequately defined as advertising wear out. This decay effect can be mathematically modelled and is usually expressed in terms of the 'half-life' of the advertising. A 'two-week half-life' means that it takes two weeks for the awareness of an advertising to decay to half its present level. Although every advertisement is said to have it's own unique half life span