Display the FREE SHIPPING option next to the "Add to Cart" CTA

Free shipping is a strong incentive for potential customers to add a product to their cart and even complete the purchase.

By prominently displaying the free shipping option in close proximity to the call to action (ADD TO CART), you will create a kind of added value for potential buyers, which will stimulate and motivate them to add the product to their cart, feeling that they are saving the equivalent shipping costs.

One possible mistake is adding the free shipping mention in the announcement bar, a place that is often overlooked. Or, in case it's not overlooked, even if they would have noticed it, after seeing several products, the user will definitely forget about it.