Nice, thanks for the numbers! At a certain point you start competing with Home Depot, Michaels, Walmart, Amazon, whoever. You are in the product retail business, rather than the manufacturing or services business.
I think if you get really good at streamlining your marketing (Instagram photos and landing pages) as well as your pick/pack/ship operations (i.e running a warehouse), then you can expand into multiple niches. Fabrics, clothes, prints, whatever is super niche and high margin and can't be found on the shelves of a big box store.