We have created two parameters ad-strength and ad-gravity to define the performance of any given ad. Here are the primary differences between the two quantities Ad-Strength () Ad-Gravity () Measures the performance of an ad over its entire lifetime Measures the performance of an ad in recent few weeks Higher value means better Higher value means better This quantity can only increase with time This quantity can increase or decrease depending on the ad's recent performance A value of zero (0) means that the ad had no traction. A value less than 10 means that ad had very little traction A value of zero (0) means that ad never had any traction in its lifetime. A value of one (1) means that the ad had traction in the past. A value > 1 means the ad has traction currently Bottomline: If you want to know the performance of an ad over long time period, use this quantityBottomline: If you want to know if the ad is performing well recently use this quantity