NEW YORK: Over a third of Americans have responded to an ad viewed on their mobile phone, and this medium is also increasingly encouraging word-of-mouth between consumers and influencing purchase decisions, a study from AOL and Universal McCann has found.

The two companies estimate that of the 63 million US consumers who have used the mobile web, 19 million do so on at least a weekly basis.

Based on a survey of 1,800 mobile users in the country, they also found that around 14% of all media consumption now takes place on a cellphone.

Some 38% of participants said they have taken some form of action in response to a mobile ad, while 30% argued these ads had caused them to share information with others.

A further 22% of respondents agreed mobile advertising had exerted an impact on their buying behaviour.

The most popular activities on the mobile web include looking up maps and directions, with 73% of the survey panel having done so, while 55% had accessed social networking sites from their phone.

Other findings included the fact that 77% of consumers use their mobile while watching television, a sign of increased "media-meshing."

Just over a quarter of participants, however, said they were "completely focused" while using their phone, compared with 33% arguing the same when it came to surfing the internet.

This figure fell to around 20% for TV, newspapers and magazines, while radio registered a comparative total of just 6%.

In terms of cross-media communications, 56% of those surveyed said they had been encouraged to access information on their mobile by content they had seen on another form of media.

Similarly, 42% stated that material viewed on their mobile had directly caused them to access a different media channel.

Data sourced from AdWeek; additional content by WARC staff