According to March 2012 research from Google, at least 24% of smartphone owners used their device to search in response to brand messages at least monthly. More than 40% used their smartphones to search in response to a television ad. Nearly as many, 40%, searched in response to ads they saw in stores.
eMarketer explains how this data points to how powerful a tool mobile can be in direct response campaigns, which is definitely true. I think it also indicates how heavily consumers are starting to rely on their mobile devices for on the spot information.