Oftenness capping: If you see the ad mesh gushing the homophonic ads again and again- then so are your users. If you aren't interested in what the ad has to bid the no. few nowadays it was shown, it's not credible that you'll be interested the 184th measure around that day. The State Law (or 80/20 dominance) says that 20% of your users consumer 80% of your guild wars gold impressions. Thus, there are a flyspeck group of users who comprise the volume of your impressions.