Now, and especially in 2003, Inventory Management of advertizing will be key. The concept of inventory management is central to our attempts to sell advertising. In the past, we've allowed weight based and open ended campaigns. Very difficult to keep track of and determine what value we have provided. Even harder to explain to the customer. So IM will require that we move to units - either impressions, or possibly a meta-unit of some sort. There will be a circular feedback loop to manage. dirgraph IM { ad_definitions -> ad_delivery -> ad_stats -> ad_definitions ; } If we know how many impressions a given position generates for a given month, we can sell those in blocks of 100k, or so. If we run out of ads for the position, house ads should rotate in. The stats on the house ads will be an indication of how well we are selling. May answer questions about appropriate rates, selling techniques, etc.