Systems and methods are disclosed herein for generating reminders to shoppers to purchase products. Using a customer's current location, products stocked at that location are identified and compared to the customer's purchase history. Items regularly purchased by the customer found among the products stocked at the location are identified. Upon departing the location without adding the product to an electronic shopping cart an alert may be generated to remind the customer to purchase the product. In some embodiment, an alert is generate for a product found in the purchase history if an elapsed time since purchase of the product exceeds an expiration period or purchase period for that product. The methods disclosed herein may be used in the context of a self-checkout using an electronic shopping cart and navigational aids to facilitate retrieval of items on a shopping list.