Look at the top and middle images below...see anything different between the two? The top image, which is a full-page advertisement by Goldman Sachs, displays a QR Code (lower left hand corner). The middle image, the same exact advertisement by Goldman Sachs, does not display a QR Code. A mistake? Probably not. An A/B split test? Probably not. So then, why the two different ads? My guess, Goldman Sachs' marketing and creative team probably thought it would be cool/hip/innovative to place a QR Code in an advertisement, any advertisement, so they simply took one of the most recent ads running and slapped a QR Code on at the last minute. Not a recommended strategy.
Even if Goldman Sachs was legitimately running a test or comparison between the two versions of the ad, I can tell the company right away why the campaign with the code will fail. How? Simple. Try to scan the QR Code. You can't. Or, at least, I couldn't even after trying up to eight different code readers. The code is too dense and too small.
On a number of fronts, this advertisement teaches a lot, a lot of what not to do when developing and implementing a 2D campaign.
2D Barcode Litmus Test: FAIL