Local courier services fill a niche that regular mail and corporate parcel carriers do not. Upheld as reliable, personalized, and perhaps most importantly, time-efficient agents of secure delivery, local courier services, also referred to as simply couriers, are the convenient and practical alternative to wasting time on a doorstep in wait of an absent shipment. Couriers cater to businesses and individuals everywhere, and can cover a radius as small as several cities or districts, or more commonly will operate across a region as large as several counties. In courier protocol, either manner of coverage is still classified as local, as shipment traffic increases, hiring is enacted or deliveries are subcontracted. Courier services specialize in one or more interests and operate via one or more systems of pick-up and delivery. Document messengers are contracted primarily by insurance and law firms, notary public, and courthouses. Some courier services offer remote document pick-up by way of drop-boxes, but this is uncommon and generally only the case in metropolitan areas. Parcel couriers specialize in a broad spectrum of materials for delivery, such as medical samples for laboratories, automotive parts for retail outlets, airline luggage, collectibles, office supplies and even food products. Multi-drop is another mode of delivery wherein couriers are contracted to receive bulk orders and deliver portions of, or the entire shipment, to one or more destination points. Thus the courier is able to meet the needs of wholesalers, distribution warehouses, and large box stores in a timely manner. For considerably large shipments, trucks will be employed in place of cargo vans. In the business of supply and demand, in-stock translates to revenue and local courier services are more than happy to help others stay in business, whether the location is central to commerce or situated in a suburban or rural zone.