Having discounts maintained separately from products is useful when it comes to applying them to a group of products / categories, but sometimes it can be a nuisance where a discount may only be applicable to a single product.
It would be helpful if there were a facility to create discounts 'on the fly' while creating a product listing. A single 'Quick Discount' field added to the product entry page could automatically create an entry in the Discounts table, with an incrementing code (e.g. QD1,QD2...) and associated with the single product. Alternatively, provide a means on the product listing page to associate an existing discount (as for Categories / Characteristics).