The reason for the lower ad rates? Marketers are skeptical that The Jay Leno Show will draw an audience on par with scripted shows airing on CBS and ABC. Fox doesn't program the 10 p.m. slot, allowing its local affiliates to fill the hour.

And a quick look at the networks' lineup for the 2009-10 season shows that The Jay Leno Show will compete against some returning powerhouses, such as CBS's CSI: Miami, as well as untested programs such as ABC's Eastwick.

Historically, the late-night Tonight Show With Jay Leno drew ratings far lower than primetime hits. His final Tonight Show episode, in May, featuring all the attendant hoopla commemorating his 17 years as host, drew 11.9 million viewers. By comparison, the season finale of Grey's Anatomy in May drew 16.5 million viewers.

NBC executives say they're hopeful about consumer "awareness" of Leno's move to primetime next week, according to Variety. About 82 percent of consumers are aware of the show; 20 percent say they intend to watch it. Some may indeed tune in out of curiosity, but the track record for drawing audiences to new shows isn't great. Most new TV shows grab their highest ratings with the show's debut, and viewers trail off in the following weeks.

Still, NBC executives see a bright side, telling The Journal that Leno's lower ad rates will compare well to the cheaper ads attracted by reruns of the scripted shows. So look for The Jay Leno Show to outpace its competitors in the dog-days of summer 2010.