Quick answer: Shopify’s native Buy X Get Y discount does not automatically place the free product in the cart. The customer must add both the qualifying item and the reward item; Shopify then discounts the eligible Y item when every condition is met.
The real symptom
A merchant creates a buy-one-get-one discount, tests the storefront, and sees only the paid item in the cart. The promotion appears broken because the free product never appears automatically.
Likely causes
- Native Buy X Get Y discounts discount products already in the cart.
- The customer did not add the reward item.
- Eligibility, dates, customer restrictions, usage limits, or combination settings block the discount.
- The merchant expected gift-with-purchase behavior rather than discount behavior.
Confirmed Community fix
Community replies repeatedly resolve this by adding the second qualifying item manually. Shopify documentation confirms both the customer-buys and customer-gets products must be in the cart before the discount can apply.
Exact admin path
- Go to Discounts.
- Open the affected Buy X Get Y discount.
- Confirm Automatic discount or Discount code.
- Review Customer buys quantity and products.
- Review Customer gets products, quantity, and discount value.
- Check eligibility, dates, usage limits, and combinations.
- Test by adding all required items to cart.
Simple checks
Test in a private window: add the X product, add the Y product separately, and verify whether the discount appears in cart or checkout depending on discount method.
Do not do this
Do not advertise that Shopify will auto-add the gift unless you have built or installed that behavior.