Obama ad will have live portion

UPDATED: Wednesday night's Barack Obama primetime ad will contain a live segment near the end of the telecast.

The much-discussed special will cut live to an Obama rally in Florida, where the Democratic candidate is campaigning today with Bill Clinton. It's not clear if the former president, who is joining Obama for the first time on the campaign trail, will share the stage during the segment.

Though going live is technically more challenging and potentially more risky for Obama should something go awry, the plan will likely result in higher viewership than a mere taped telecast. The move also further explains why the Obama camp insisted on having all its ads run during the same 8 p.m. time period. 

The special -- titled "Barack Obama: American Stories" -- marks the first time in 16 years a presidential candidate has purchased a national address before the general election.

The telecast should provide a unique test of the electorate's current interest in Obama's messaging. Campaign ads, after all, are typically considered a nuisance best avoided rather than Must See TV -- especially in swing states, which have been bombarded with every flavor of political advertising in recent weeks.

But given the heavy interest in the election in general -- with convention speeches and the debates managing to set Nielsen ratings records -- curiosity tune-in could be high. NBC, CBS, Fox, MSNBC and Univision are among the best known outlets carrying the telecast.  The Obama campaign has spent an estimated $3 to $5 million  on the ad buys. Obama will also be a guest on Comedy Central's "The Daily Show" tonight.

Ratings for paid programming are often not released to the public, and Nielsen was still mulling on Tuesday whether to announce the ad's viewership. Given the heavy media interest, a release seems likely.

The question is, what's a good number? Ross Perot's 1992 specials averaged about 11.6  million viewers. Obama's convention speech was viewed by about 38 million viewers. Broadcasters average about 7 to 9 million viewers in those time periods.

But none of those seem like proper comparisons -- Perot's speech was only on two networks and were part of a series of informercials; Obama's speech was 100% live and concluded several days of convention coverage, and comparing entertainment programming to an infomercial is problematic. Unless Obama's viewership is spectacularly high or low, attaching a relevant meaning to the audience measurment could be difficult. 

UPDATE: The Obama campaign provided The New York Times with a trailer from the taped portion. The footage is described as--

"...heavy in strings, flags, presidential imagery and some Americana filmed by Davis Guggenheim, whose father was the campaign documentarian of Robert F. Kennedy. As the screen flashes scenes of suburban lawns, a freight train and Mr. Obama seated at a kitchen table with a group of white, apparently working-class voters, Mr. Obama says: “We’ve seen over the last eight years how decisions by a president can have a profound effect on the course of history and on American lives; much that’s wrong with our country goes back even farther than that.”

The Times added that the content will highlight the stories of four American families and the challenges they face.

UPDATE II: Barack Obama infomerical released -- VIDEO

UPDATE III: TV critics praise Obama infomercial

Previous posts on this topic: "Pushing Daisies" creator Fuller hopes Republicans save his show ... CNN rejected Obama ad; Fox News not asked ... Thoughts on "The Obama Show" ... Obama buys half-hour of network primetime.

Other takes: Washington Post -- "Axelrod: Obama TV Show to Focus on 'Where He Wants to Lead'  ... Stephanopoulos: "However the rest of the time you might see other people, like a Warren Buffett or a Colin Powell, and other people the Obama campaign calls "validators" to give testimony on why Americans should vote for Obama." ... Lisa de Moraes -- coverage rundown ... Politico: "Smart politics or risky overkill?"  ... TVWeek: "Will viewers tune in?"