• by Mark Walsh  @markfwal, November 11, 2010

During Facebook's press conference last week rolling out new mobile initiatives, CEO Mark Zuckerberg caused a minor stir when he asserted the iPad wasn't a mobile device. The episode highlighted the debate about whether the iPad and other tablets are more like smartphones and other mobile devices, or more like a laptop or PC.

Trying to shed more light, or heat, on that topic Thursday was a panel of executives from digital media and ad companies including Transpera, TargetCast.com, Zumobi and Kargo. They're intrigued by the potential of the iPad and other tablets for brand advertising, but find the audience hasn't yet materialized to make such devices  a viable ad category.

In that sense, the tablet market is still too inchoate to classify either as a larger smartphone or a handheld PC. Frank Barbieri, chief product officer of mobile video ad network Transpera, said the company doesn't focus so much on the larger screen size of the iPad compared to the iPhone, for instance, but on the context of where it's being used.

So if the iPad is generally being used more at home than a smartphone, it will more likely have a WiFi connection, allowing Transpera to serve richer, more bandwidth-demanding ads than if it were sending an ad to someone using the iPad on the go with a 3G connection.

Steve Minichini, president of interactive marketing at media agency TargetCast, emphasized that mobile phones have the advantage for now because of the large audience they can deliver. "If we want reach, mobile is the play," said Minichini, speaking at the Digital Hollywood Summit in New York. "But we'll see what happens as the [tablet] numbers change next year." He acknowledged tablets won't approach the reach of smartphones anytime in the near future, though.

Likewise, Jon Tuck, VP of sales and sponsorship at mobile ad firm Zumobi, said the company won't even create a branded iPad app unless strategists believe they can really monetize the app, because an audience of 4 million iPad owners isn't big enough to justify the expense.

Harry Kargman, founder and CEO of Kargo, which helps publishers adapt their content for mobile, mounted a counterintuitive defense of the smartphone's smaller screen. "We think there's an advantage on smartphones because the screen is so small that the ad itself takes up a much larger part of screen real estate," he said. On a tablet, the same ad might not command as much attention because it's more like a typical banner ad on a computer screen. "I don't know that big necessarily equals good," said Kargman, arguing that ad-to-screen ration is what counts most.

But Bill Reynolds, media director at South Carolina-based agency Erwin-Penland, said he welcomed the iPad's larger screen as a way to expand mobile media to a more mainstream audience over time.

Despite the differing viewpoints, it's clear digital marketing experts are looking at the tablet as a distinct platform from smartphones, especially concerning the addressable audience at present. As to whether the tablet will line up more with the smartphone or the PC as the user base grows, that debate will likely go on for some time.