I'm using Drupal 7 and Drupal Commerce Module. I'd like to be able to provide customized links with promo codes in them (promo codes would be a key/value pair in a format like www.url.com/?promo=specialK or some such thing). So Group A, for example, would get their link and click on it and it would bring them to our Registration/Product page form.
This would be the same form for every group with different discounts applied to the product price depending on the promo code attached to the URL.
If the promo is expired I'd like Drupal to just give the user a page that says something like 'Your promo is expired. Sorry. blah blah blah.' However, if the promo is NOT expired it would just apply the discount to the price and let them fill out the rest of the form and submit their payment information, etc > the normal drupal commerce procedure with the discount applied.
I'm thinking of approaching this with Drupal Coupon module to enable the discounting functionality, but I don't know if it's possible to use a URL to pass that promo code automatically to Commerce. Does anyone know?