Examples of delivery and/or referral services

A method comprising:

• receiving information regarding inventories of a plurality of merchant from a plurality of point of sale systems;
• receiving an indication of a delivery order that a customer places with a first merchant of the plurality of merchants;
• determining a plurality sources of items for a high speed delivery of the delivery order to the customer based on the reported inventories of the plurality of merchants;
• determining one or more delivery agents for making the high speed delivery from the plurality sources to the customer;
• determining a cost for the high speed delivery of the delivery order;
• in response to determining the plurality sources and the cost for the high speed delivery of the delivery order, transmitting information identifying the cost;
• receiving an indication that the customer desires the high speed delivery of the delivery order;
• in response to receiving the indication that the customer desires the high speed delivery,
• determining an unavailability result, by determining whether at least one first item of the items is unavailable for delivery based on a condition of the high speed delivery for the at least one first item using location information received in substantially real time, via a communication network, from substantially real time tracking of location of a mobile device of at least one mobile delivery agent of the one or more delivery agents, and
• communicating, via the communication network, to populate a graphical user interface of a point of sale system of at least one of the plurality sources with an indication whether the at least one item is determined to be unavailable for delivery based on the unavailability result;
• and
• in response to receiving the indication that the customer desires the high speed delivery, facilitating the high speed delivery of the items from the plurality sources using the one or more delivery agents.