QR codes. What's the point?

Apparently these are now the latest thing in marketing and providing links to your web content. I'm not normally a tech phobic person but I don't see the point of these codes. See below for what I'm talking about. (This is the QR code linking to this blog)

So to make these work you need the following:

1.  A smartphone, be it of the Apple or Android variety.
2.  An app that can translate the QR code to something meaningful.

So for me I need to start an app on my iPhone, photograph the code and wait and see if something happens. If it works it eventually directs me to a bit of web content related to the advert the code is on. On my iPhone this takes a couple of minutes (maybe the software and hardware are slow) but why not just put the URL on the advert instead. Its a lot quicker to copy this down into your browser.

Maybe I'm wrong, who knows?