Place the message where intent is highest
A free shipping bar is most effective when shoppers can see it while evaluating products, viewing the cart, or making checkout-related decisions. The goal is to surface the incentive when it can still influence cart building.
Keep the copy focused on progress
The strongest messages are usually short and specific. Showing the remaining amount creates a clearer next step than a generic promotional banner.
Match the design to the storefront
A lightweight progress bar that feels native to the Shopify theme will usually outperform a bulky interface. Merchants want the offer to feel helpful, not disruptive.