According to a report by analysts The Nielsen Co, around 23-percent of US cellphone users have seen advertising on their handset in the past month, and - more surprisingly perhaps - about half of them responded to those adverts.  Surveying 22,000 individuals who actively use mobile data services, Nielsen’s researchers found a 38-percent increase in mobile ad recall between Q4 and Q2 2007. 

Around 13-percent of those questioned said they would be open to adverts if it improved the mobile content available, while 14-percent stipulated that they would accept marketing messages consistent with their own interests.

In terms of demographics, Nielsen claims Asian-Americans and African-Americans are more likely to recall mobile ads than other users, and that the 13 to 17 age range displayed the greatest attentiveness to marketing.  Almost a third of people would apparently be open to cellphone advertising if it lowered their overall bill.