One of the reports on the Mission Control screen is the Potential missed opportunities report.  This report was designed to show you where you are no longer spending money, but the leads you originally found from that source are still spending money.  The use case which shows the value of this report is when you run an ad and generate a bunch of new leads, but they don't spend any money with you.  So, 3 weeks later you turn the ad off because it seems to not work.  Then 2 months later, those leads start spending money.  You may have found very valuable leads who are now spending money and they just took time.  You may want to turn these back on as they actually worked...it just took some time.

Below is a video to show you exactly how this report works.