ADU(Audience deficiency units are units of inventory that are made available to advertisers as fulfillment for the inventory the advertiser purchased that ran in programs that under-delivered on the guaranteed ratings. tar)
core audience(the type of people who are most likely to buy a particular product, watch a particular TV programme, etc.: core audience for something > The core audience for the yoghurt drink is young people on a diet. Definition of core audience noun from the Cambridge Business English Dictionary. Alexander Demidov)