QR Codes

QR code for Three Fates Design etsy store

I've been thinking about adding a QR code to my business cards.  Does anyone have any experience with using these?  Do people seem to use them, or are the not worth it?  The above QR code links to my etsy store.  I thought maybe I would stick one for my blog on my business cards (since there is a store link on there already).  

QR code for Three Fates Design Blog

They are kinda cool because you just them with a free QR scanner that you can download on your phone.  There are a lot of them out there and they are normally free.  You just scan them and it takes you right to the website.

I would love to hear if anyone else is using these and how useful they are.