I agree with Paul and would add, that you might try diversifying product offerings to add more common, regularly available products (therefore steady revenue) and then put focus on your OOAK products with pop ups, to newsletter subscribers.
This will accomplish one major thing - increased visits/engagement
1. Increase repeat customer visits and purchases
2. Give you a platform to highlight OOAK items and create excitement (when they're gone, they're gone) - customers love this and it will increase their engagement on the site, always waiting for the next unique item to be released.
3. Provide valuable content and ads content for social media around the highlighted products.
Hope this is helpful.