In theory it made sense. If you have positions in wireless, TV and internet, you should be selling integrated ads across all three platforms. But AT&T, which announced a strategy to do just that less than a year ago, has hit a bump in the road. According to The New York Post, the telecom giant has suffered personnel setbacks while failing to hook customers on U-verse, a three-in-one cable, phone and internet package.

AT&T spokesman Michael Coe said, "We're still evaluating our platform and business model."

In the meantime, Karl Spangenberg, an ad sales veteran, has left the company. No replacement has been found. To compound matters, U-verse has only managed to attract 126,000 customers, a far cry from the 65 million people who subscribe to AT&T's wireless service.

"The first issue is reach across all three screens," said Jupiter Research advertising analyst Emily Riley. "Generally, the same company does not control the same audience across all three."