Systems, methods and/or services that allocate and schedules appointments based on supply and demand. In an example, a method is implemented in a computer infrastructure having computer executable code tangibly embodied on a computer readable storage medium having programming instructions operable to: gather information of a plurality of suppliers from one or more external sources, prior to a registration process for scheduling an appointment request from a consumer; validate the gathered information of the plurality of suppliers; receive a request from the consumer for scheduling of an appointment with one or more of the plurality of suppliers which meet consumer criteria; enable swapping, purchasing and auctioning of appointments; enable virtual visits and virtual visit queues for on demand virtual appointments; provide system agnostic calendar integration, and provide available suppliers to the consumer based on the consumer criteria.