I've found them horribly useful for passing authentication tokens from desktop to mobile devices. It means that you can move tokens without having to type enormous screens or go through a normal login form.
QR codes on billboards and in marketing are kind of rubbish, but in terms of moving a URL or a phone number from your PC to your phone quickly, they're actually pretty useful.
What determined the outcome of your service was the convenience factor. To use it, the user needs to select the information, go to your webpage, and then submit it. It's too much work for the user.
OP's program removes 1/3rd of the steps, making it much easier for the user.
QR codes on billboards and in marketing are kind of rubbish
On a big billboard beside the freeway, sure. In a home for sale sign, or in a bus shelter, or anywhere else where people are either a) very interested or b) captive, they are fantastic.
I find it useful, it just needs to be easier on phones to get to the qr code scanner. I use an iphone, and if it was as easy as just opening up the camera app, pointing at the code which it recognized and put a box around (similar to the focus box perhaps) that I could click on, it would go a long way to getting more people to use them.
