do qr codes help

While doing some reading i kept running across a lot of people suggesting qr codes. I was curious while doing legit content is it advisable to qr code the page? if so would it be more advisable to qr code the page you are on like domain/subpage or just hit the root of your site?

thanks

I know people like to use QR codes on the back of a business card to get people to leave reviews on their places page, as that is extremely helpful in ranking places.

ok now i'm curious should the qr code point to your google places url or your homepage url?