Blaming "audience fragmentation" that has resulted from viewers withdrawing from broadcast networks and switching to cable or Internet viewing, a study by TargetCast has revealed that lower ratings resulted in an 11 percent drop in the average cost of a primetime commercial during the fourth quarter of last year versus the comparable quarter a year ago. A primetime spot on network television cost $105,821 on average, with Fox leading the pack with $122,098 per spot and NBC trailing with $76,436. In a news release, TargetCast said that ABC and CBS were "not far behind" Fox, but it did not specify the average spot cost. Lower ratings were not the only reason for the plunge, TargetCast executive Gary Carr indicated, pointing to the high number of spots sold during the upfront market when networks drastically reduced prices in the face of the economic decline. On the other hand, cable showed only a tiny 2 percent decline overall, with several cable channels showing hefty increases. ESPN commanded the highest rates of all the cable networks, averaging $40,000. Well down in second place were the USA and TBS channels at just under $18,000.