Coming off a surprisingly strong fourth quarter,

Coming off a surprisingly strong fourth quarter, broadcast network sales executives are predicting that 2006 will be a solid, if not spectacular, year for growing ad revenue. Advertisers and media agencies are rumbling that they will begin to demand more tangible proof that their ad spending is resulting in a solid ROI. If not, they threaten, they may begin to move dollars elsewhere. But broadcast executives believe the average $24 cost-per-thousand for a 30-second prime-time spot is still an economical way for most advertisers to get the immediate mass reach, or even targeted reach, they need to remain competitive.