Nightly network news viewership is irrelevant. It's on once a day for half an hour. Local news viewership is higher because it is on more frequently. In 2008, 29% of respondents told
Pew that they watched a network newscast yesterday. 52% said they watched their local newscast. Local newscasts were still the number one source for news in 2008, according to Pew. That's
still true in 2010 - local TV is the top news source for Americans on a typical day, with 78% of Americans telling Pew they get news from a local TV station.