Getting a banner to appear for each product of a particular category

I offer free shipping and other enticements for the decorative hardware category of my store. On this category page I currently display a banner outlines these features.

The problem is when a customer does a search for a particular knob (via its model number and brand) and lands directly on the product page, he won't see my offerings and will likely click away.

Is it possible to have a banner appear at the top of every product page in my “Knobs and pulls” category, without doing it manually for each and every product?

Which version are you on? You could create a custom template to do this, but it would require various if statements for all of your categories (something like. if product is in category ID 1, show X, else if in cat ID 2 show Y, etc).

Another solution may be to display products from within the same category which I built an addon for in V2 and V3.