Ordinarily Thursday is television's biggest night of the week. It's also thenight when advertisers spend the most. But those advertisers will likely beunhappy with what they got for their money on Thursday of this week. asaudiences declined across the board. ABC aired the live finale of itssinging-competition series Duets but drew just 4.5 million viewers.NBC's series, The Office, Parks and Recreation, and SavingHope produced barely a blip on Nielsen's ratings chart, averaging fewerthan 2.2 million viewers. Its highest-rated show of the night was thefloundering Rock Center with Brian Williams , which counted 3.4million viewers. Fox also averaged fewer than 2.7 million viewers for theweek. That left CBS to pick up the spoils with a slate of reruns thataveraged just 6.5 million viewers.