For the past three years ad agency/CMR TMP Directional Marketing (and now its search agency 15 Miles) have been studying local search behavior, using comScore's panel. During the past two years there's been a local-mobile component to the survey (n=4,000 US respondents). The chart below shows use of mobile devices to find local information (directory assistance is one of the choices):
What the data reflect is that among these respondents 60% of smartphone owners have conducted a local search through an app or browser, while only 19% of non-smartrphone owners have. This goes to data pricing and cost factors as well as usability.
One interesting fact: smartphone owners (in this survey) don't seem to be substituting the mobile Internet for directory assistance usage. That may be because they tend to be more affluent and less price sensitive. But compare that with the attitudes shown in our April, 2009 survey (second graphic below) about the relationship between traditional DA and the mobile Internet.
Source: comScore-TMPDM/15 Miles (10/09)
By contrast, we found that smartphone owners and those intending to buy smartphones were in general agreement with the statement that the mobile Internet was a substitute for traditional 411:
“Now that I can get the Internet on my mobile phone I no longer need to call 411”
Source: Opus Research April, 2009 (n=707 North American mobile users)