Allow URL Anchor or URL Query String to give direct access to promos instead of typing in promo code.

I get that promo codes generally aren't very difficult, but as a tech guy at a newspaper I run into customers who just seemingly find a way to create unnecessary issues.   I think it would be neat to be able to add something in the Subscription URL so that the promo codes are already displayed.  

Example:   www.tdtnews.com/users/admin/service/purchase/?serviceid=478#RESUB would take you to the online-only subscription page, but the #RESUB or ?RESUB would activate the promo code without needing to type it in.  

Thank you,