residual traffic model?
 

Has anybody figured out a model for the behaviour of traffic after a campaign? In other words, when you stop a campaign, traffic falls off but is there a residual traffic stream and subsequent sales 3,6,12 months down the road? Does profit fall off exponentially or reach a baseline higher than before the campaign?

i still get sales off of stuff from 2 years ago. The set it and forget model i used back then