Also called the "gig economy," "sharing economy" or "instant gratification economy," the on-demand economy means getting something, if not immediately, sooner than they could in the past. The poster child is the Uber transportation service, and startups in this field call themselves the "Uber of X" (Uber of food delivery, Uber of private jets, etc.).
Freelancing, Sharing, Apps and the Internet
Freelancers (part-time drivers, landlords, etc.), and shared facilities (cars, rooms, etc.) are major factors in the on-demand economy. The smartphone has been the catalyst behind all of this because people have gotten used to getting instant answers any time, any place. See Uber