scatter market
n.— «Demand for television ad time sold closer to the actual air date—what is known in the industry as the scatter market—is plummeting as TV ad execs report that their phones are eerily quiet during what is normally a busy time of the year.» —“TV Ad Sales Execs Say Scatter Market Is Shot” by Holly M. Sanders New York Post Nov. 5, 2008. (source: Double-Tongued Dictionary)