A majority of mobile users report seeing ads on their phones and nearly a quarter have responded to those ads, according to a new study sponsored by the Direct Marketing Association. But high response rates haven't translated into a mobile awakening, and once again carriers are taking the blame.

Edward T. Manzitti, VP for research at the Direct Marketing Association, called mobile one of the hottest marketing channels out there. But he warned that the medium isn't likely to be a hit until carriers find a way to let marketers, not users, foot the bill for messages.

"If the carriers offered marketers a different type of pricing, where the marketer paid the cost rather than the consumer, you'd see a different type of response," Manzitti told The New York Times in response to reports that many users were angered by the cost of getting an ad on their phones.

While direct marketing is expected to make big gains in the next few years, the prospects for mobile don't appear as bright. Despite positive responses from users, carriers have been slow to work with marketers.

The study also found that users with AT&T and T-Mobile were more likely to respond to ads. However, researchers were unable to determine if AT&T beat Verizon because of a more liberal text message billing plan or because of the iPhone.