threshold effect

1. General: Radical change of state within a system whether a physical system like the human body or an abstract (conceptual) systems such as an economy that often manifests suddenly when a critical limit is crossed. For example, a disease or syndrome may appear without warning after a long period of quiet development, or investor confidence in a financial system may disappear overnight after years of mismanagement.

2. Marketing: Cumulative effect of a sustained advertising campaign that brings about customer recognition of a brand or product in the form of a significant jump in sales revenue. The expenditure level at which this effect occurs is then used as a benchmark for setting future advertising budgets.