So what I'm trying to achieve is to use Products within the Collection Page grid, as simple advertisements / direct link images to break up the flow somewhat.
Here's how my less-than gurulike imagination sees it conceivably working..
1. Create a Tag such as 'Promo' for products we want to convert to Promo Image Linkboxes in the product grid.
2. While we're here, add a metafield for the Link URL we would want the Promo image to take us to.. i.e 'Read our Blog' with a Blog URL, or 'Explore this other Collection' with a Collection link etc.
3. Then this is where you come in (hopefully) - we'd need to create a bit of liquid logic for the Collection Page that says something along the lines of 'IF any product is tagged as Promo, THEN bypass the standard product layout and use an alternative template/snippet to convert it into just an image box that uses the direct link from the metafield above'
4. Style up just such a template so it's an image with the custom metafield URL (so not directing to a Product Page as it would normally) so the Collection Page has something to look to for these unique 'products'
I'm hoping there are some lounge wizards out there with some spare minutes to guide me into getting this going. Appreciated.