A "There's Only One October" campaign, featuring stand-up comic Dane Cook, will highlight some "memorable postseason moments, while showcasing today's teams and most promising players," the organization that operates North American professional baseball's two leagues said.
The Fox Broadcasting Co., which will air this year's American League playoff series, and the TBS cable network, which will air the National League series, will run spots tailored to each of their brands.
Commercials will also run on TBS sister networks CNN and TNT, Fox sister network FX and the ESPN sports network.
Radio spots will air on ESPN Radio and XM Satellite Radio, MLB said.
Print advertisements will include Sports Illustrated and USA Today.
The campaign also includes an "actober.com" Web site featuring more than 60 video clips of postseason baseball footage.
Users will be able to "create their own actober moments and win tickets to the 2007 World Series," MLB said.