You just made my life easier because I have to go to your website to ensure I have your address and contact information on hand and in my mobile device. Your page comes up and I'm about to perform that high speed hunt we've all done a million times before but I stop. I see you have a QR Code and I wonder: are you actually that smart that you have anticipated my needs so completely that all I have to do is scan the code on your webpage and all the pertinent information will leap into my cell phone? Sure enough, there's a GoogleMap linking to your office location and your phone and email in case anything else pops up on the way! You just saved me time and time, as they say, is money. Which means I think you're a pretty cool dude or dudette.
QR Codes: Anywhere you have physical OR digital space.