摘要: AirBnb, the website through which users can rent out their home to overnight guests, is valued at $1 Ob and has an estimated 800,000 rentals listed in 34,000 international cities. Uber, the ride-sharing service, also dominates its sector and has a valuation of no less than $40 b.Although these are the most successful, a variety of smaller start-up firms are revolutionizing industries: they are provid ing alternative, crowdsourced services in areas ranging from meals (SupperShare), package shipment (PiggyBee), car or boat rental (respectively, RelayRidesand Boatbound), home delivery of goods (Instacart), and even contracting with short-term laborers (TaskRabbit, Air Tasker, Proprly). Their services build upon the well-established repertoires and rhetorics of local exchanges such as community-supported agriculture (CSA) programs, neighborhood tool-sharing, time banks, and the like, but are now using mobile …