QR Codes Fad or For Real

A QR code  is a matrix bar code.  They are likely to appear in print advertising.

I am just not sure what purpose they serve.  The ones that I have seen just clutter the page.

And most of the ones that I have clicked on, for the most part serve no purpose other than take me to the company's homepage or if its a contest to that page to enter.

Question. You have invested in a website. Why not use every bit of advertising to brand your website address?