An entrepôt is a trading centre, or simply a warehouse, where merchandise can be imported and re-exported without paying import duties, often at a profit. This profit is often possible because of trade conditions, for example, the reluctance of ships to travel the entire length of a long trading route, so it sells to the trading centre instead. The trading centre then sells at a higher price to ships travelling the other segment of the route.

Singapore, and the Cape of Good Hope were prominent examples in history, and some still are today. For example, ships were reluctant to travel all the way from Britain through the Suez Canal or the Cape of Good Hope through the Indian Ocean, through the Straits of Melaka to Shanghai, so they sold to key ports along the way, then returned back to their original port, in this case Singapore and the Cape of Good Hope. Other ships coming from the other direction would come and buy the goods, at a higher price to sell at their next stop.

In the Middle Ages, this was especially true. There was demand for spices, but a long trading route, thus leading to a much higher market price than it was originally bought for when the spices reached land. This led to an attractive profit for those who bothered to travel the entire route constantly.