The T-Mobile acquisition by AT&T would create the largest mobile carrier in the U.S. bar none. However, since neither company has invested heavily in mobile advertising, it’s not expected to have much effect on that industry . . . unless AT&T decides to leverage customer date for targeted mobile ad campaigns.

The advent of smartphones has led to the advent of a $1.2 billion mobile ad market that includes Google’s AdMob and Millennial Media. Mobile advertising wasn’t really taken seriously until the advent of smartphones, said Sarah Baehr as svp, director of digital publishing solutions at MediaVest. Some paid media dollars are going to buy mobile ad network display, but more money is starting to flow into mobile social, in-app, branded apps, deals and shopping. That’s where the center of gravity is moving to.

The real golden ring for mobile is customer data. In the past, carriers were dead set against it, said Phuc Truong, managing director U.S., of the mobile marketing firm Mobext. Lately they’ve listened more.

With over 130 million users, the combined entity of AT&T and T-Mobile could reach out to a vast audience with targeted ads based on geography, household size and spending habits. The data could also be sold to an outside party to manage the ads. They’d have to do it in a way that avoids using [consumers actual names]. But that’s the really interesting part of this deal. The carriers definitely don’t want to become just dumb pipes like the ISPs, said Truong.

Source: Ad Week