How to insert a banner between the products in the catalog?

Question

HTML

Hello, it is necessary that in the product catalog, let's say closer to the end, there should be banners between the products. It's not a problem to make banners, how to put them in there?
Here's how to:

Answer 1

on js. A primitive example of the essence itself:

$( ".product:eq(3)" ).after( "<img src='banner.jpg'>" );