Need feedback on redeeming a discount code on my site

[SumpinSpecial]

Hey guys,
For the last year I've been setting up business "partnerships" with rescue groups which seem well-received but never used. Would like someone to check my site and give me feedback on that. The way it works is that I set up a unique discount code for the rescue organization and email it to them. They're free to publicize it at will, distribute it to anyone they want. The shopper is supposed to enter it into the discount field when they check out in my online shop, to get a discount. (That also flags their order to me on the back end so that I know to send a donation to the organization.)

A few people that I know "belong" to those organizations have shopped with me, but not one has ever redeemed a discount code (except for me). It's possible that people are just forgetting, but I'm skeptical of that. Could someone here add an item or two to their cart in my shop (url is below), and start the checkout process and let me know what your experience is? (You can bail out before paying.)

Is the discount field too hard to see or find? Is it in the wrong place? Something else?

[Harold Mansfield]

Try making the discount code area stand out more. It's really light, and even the button is a very light grey. I can imagine people without perfect eyesight could look right over it and never see it.

I may try putting a header over it that says something like "Do you have a discount or promo code? Enter it here." To remind them that they do have one and to find it.
And then darken everything from the placeholder text to the border around the field. I may even change the background color of the area to make it stand out even more on the page and make it look like a special field, not just one that blends in with the standard order info.

[SumpinSpecial]

Thanks Harold, I'll do those things. That's exactly the feedback I was looking for.