[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/images/10/30/art.obamaad.cnn.jpg caption="Obama's 30 minute ad was watched by nearly 30 million people."](CNN) - The major networks may just wish Barack Obama took up more airtime after taking a look at the ratings for the Democratic presidential candidate's 30-minute infomercial Wednesday night.
According to preliminary ratings numbers from the networks, more than 26 million people watched the program on CBS, NBC or Fox. That's 3 million more than usually watch those networks at that hour, according to the Hollywood Reporter. Averaging in the cable networks that also carried the event, about 30 million people in all saw the long-form campaign ad.
The ad was most watched on NBC, where nearly 10 million viewers tuned in. More than 8.5 million watched on CBS while just under 8 million viewed the program on Fox. On average, about 7 million people usually tune into each network at that hour.
Overall, according to Nielsen, for the six networks that aired the infomercial simultaneously, it scored a household rating of nearly 22 percent - meaning 22 percent of all households watching television at that hour tuned into the spot. That compares to the 38.3 household rating the last presidential debate scored.
Obama's combined audience beat the highest rated television show last week: CBS' CSI drew about 20 million viewers. It also drew more than double the viewers the average World Series game this year did.
But even if viewers didn't catch the spot when it first aired, clips of the program have repeatedly been broadcast across the cable news chanels Thursday, maximizing the Illinois senator's exposure in the crucial remaining days before Election Day.
"The strategic brilliance of this for Obama is that he is going to consume about 24 hours of the news cycle," Evan Tracey of Campaign Media Analysis Group said. "It boxes [John] McCain in, takes the oxygen out of the room."
It's unclear exactly how much the Obama campaign spent on the commercial in total, but estimates put the cost at least $3.5 million.