Among those executives already in mobile marketing, optimizing websites for mobile devices held the top spot as the most frequently used mobile marketing technique, cited by 70% of respondents. In second place were mobile apps, used by 55% of these marketers. Interestingly, 49% said they used QR codes, despite some unfamiliarity among consumers with what the codes are and how they are used. The advantages of these 2-D barcodes, which allow marketers to leverage the visual engagement of print ads and lead their audience to mobile channels, seem to outweigh any consumer confusion. Read the rest at eMarketer.