According to advertising tracking firm Competitrack, 2D barcode usage in print ads increased drastically in 2011, from less than 0.9% in January to more than 6% in the last months of the year– nearly a 600% increase. Competitrack says more than 2,300 U.S. advertisers used 2D codes in their ads last year. The firm monitors 2D codes in six media: print, TV, outdoor, online display, online video and opt-in email. The vast majority — 96% of the codes –ran in print.