Some contractors might say, "That has already happened in my business." Distributors and wholesalers make deliveries to their door, and sometimes even directly to jobsites.
OK, try this one on for size: Envision a time when electronically managed inventory will be tied from an end-user's building, through the contractor, and back to the distribution center. As an equipment failure occurs, the information is sent to the distributor and a truck is on its way to the contractor's place of business with a replacement item for restocking, perhaps before the service call is completed.