That's it exactly Neil, people are so used to "instant" everything. QR codes also allow you to very accurately measure their use as they can have specific landing pages to track how many visitor etc and what they do while there. Then you can find out more about what's working and what's not.
I believe if you're not in on theses things somebody will be and benefiting. It's like the Google remarketing stuff, I 'FELL' FOR IT, i'd been looking at a sound system and obviously Google remarketing was on the site I'd visited as everywhere else I went after this companies site their remarketing ad followed me around. I gave in when there it was, about the fifth or sixth time i'd seen it a couple of weeks later, an offer for £20 off. Now the mad thing is the unit was £40 more than I could have bought it for so even with £20 off it was still £20 more than I could have paid BUT they kept reminding me i'd looked at one, and i bloody bought one.
It's not tricking people, so when I say I Fell for it, I mean, that company just kept showing me something they knew I was interested in until I bought it, it's about helping your client make the buying decision and if it's right for them they will thank you for it an come back time and time again, win/win.
Al.