O reclama dintr-o anumita perioada de timp poate continua sa aiba efecte in perioade ulterioare. Modelarea efectelor publicitare si planificarea programelor de advertising trebuie sa ia in considerare astfel de efecte intarziate. Aceasta se poate face fie prin derviarea intarzierii direct de la informatie sau prin factorul standard de carry-over(vezi Adstock). Proportia efectului necontinuat se numeste 'decay'.
An advertisement in one period of time may continue to have an effect (carry-over) into subsequent periods. The modelling of advertising effects, and the planning of advertising schedules, need to take such lagged effects into account. This may be done either by deriving the lags directly from the data or by a standard average carry-over factor (see Adstock). The proportion of the effect not carried over is called 'decay'