The writers strike is affecting TNS Media Intelligence's forecast for ad spending in 2008.

TNS predicts spending on network TV to increase 2.7 percent from 2007, mainly due to the summer Olympics and political ad spend.

But broadcast TV's loss may be cable's gain: Swallen said that once networks run out of new shows, viewers are likely to migrate to cable.

TNS also predicts online spending will see the biggest increase at 14.4 percent.

The gain results from budget cuts in newspapers and radio advertising, which will fall 1 and 0.3 percent respectively.