[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/images/09/30/art.obama.ad.a.jpg caption="The Obama campaign has previously run a two-minute commercial; today it announced has purchased 30-minute blocks of time on the broadcast networks."]
(CNN) - Barack Obama is buying 30 minutes of airtime on the major television networks just days before the presidential election, the Obama campaign confirms.
Sources with the Obama campaign say half hour blocks have been purchased on Wednesday, October 29 on CBS and NBC. The campaign is also in negotiations with Fox, though that day will conflict with the World Series if there is a game 6.
The buy was first reported by the Hollywood reporter earlier Thursday.
Evan Tracey of Campaign Media Analysis Group, CNN's consultant on ad spending, said it was unclear how much the blocs of air would cost, but noted 30 seconds alone in primetime usually runs between $80,000 and $125,000.
"This is a big platform, this is a big megaphone, the interest level is clearly there and people will watch," Tracey said.