How is Amazon able to predict what shoppers will buy before they click to order? The website tracks customer’s online search history, order history, shopping cart items and length of time spent on certain pages, the Wall Street Journal reported.

In the patent document, Amazon says delays between ordering and receiving purchases “may dissuade customers from buying items from online merchants.”

In an attempt to get customers to shop online more frequently, Amazon says it will box and ship products it expects customers in specific areas will want, based on their previous orders and other factors, but haven’t yet ordered. The packages could wait at shipping hubs or on trucks until the order is actually placed on the website.