I'm busy with this qr stuff marketing and trow in a new twist. First we need a target market for smartphone users: http://www.mobango.com/users/topusers http://www.zedge.net/people/ Or google for more phone communities Ok now you got a millions of smartphone users. Second step is create some QR codes that need to be attractive in your niche (this is a sample for a date affliate/video content locker): I used this generator and use the option to leave the background Transparent. I used this generator and choose the graphical option to insert a picture. For this one you can use any standard QR generator, just take a picture and edit in your photo editor. Ok your done, now just add friends, use option like users online, male etc. whatever fit your niche. You can use this method also for forums as a avatar or use it on FB and Twitter and add target followers.