Most travellers plan their trips ahead because it is most likely a leisure trip. These travellers try to get the cheapest airline tickets possible by booking early. For these leisure travellers, they are very sensitive to prices because they can always move their dates where the airfare is cheapest. However, for business travellers trying to get to New York from San Francisco on Monday on an urgent date, they don't have much of a choice but to get into a flight regardless of the price. Airlines take advantage of this scenario by targeting urgent travellers who most likely book their flight a day before or even at the same day. By charging at full price for business travellers, they can assure a fully loaded flight by charging less to early bookers and full price on urgent last minute trips.