We are often asked why we don't add promotional items automatically to the basket, rather than require customers to do this.

There are several reasons. Firstly, a promotion may not give a free item. It may be buy A get 50% off B. In such cases, the user has to decide whether they want the additional item at that reduced price, or not. We cannot automatically decide for them.

Secondly, the promotion may be buy A get B free, but this 'B' might be a product with several versions or be an options product. So we have no way to know which version a user wants, or what options they might want even if we know the item will be free and so they'll almost certainly want one.

In some cases, a promotion may 'gift' a specific version for free, so there is no doubt that a user would benefit from having this item. But for consistency, we don't add it in such cases. The page where the item is, as well as the basket will highlight the promotions that are available on these items, but the ultimate decision to add items to the basket is for the customer, just as it would be in a regular supermarket. If an item is buy one, get one free, a nice cashier (if you can still find a human) might let you know about it if you only have one in your basket. But it's still up to you to go get it - they won't keep them under the till in order to add it for you.