I like your questions, Fugazi. They let people who aren't node cult geniuses participate in discussions. Please, keep asking.

Also, I like your idea.

"Targeted advertising."

If Rendo wanted to set up thematic categories, they would not have to be inflexible, and there would be no reason merchants couldn't choose which categories they wanted their products to be assigned to. Nor any reason why an item couldn't exist in multiple categories.

The advertising categories that you would see most of could be linked to your past purchases, of course, or to recommendations by merchants you've bought from, and even to your favourites in the galleries.

I don't know how hard this would be to implement. But I think it would improve the overall experience here.