1. A method for efficiently deploying and managing configurable virtual server instances, the method comprising: a. receiving from a user i) a policy to be associated with a virtual server configuration and to be used for deciding when to instantiate virtual server instances corresponding to the configuration, the policy including an instruction for instantiating the corresponding virtual server instances, and ii) an identification of a virtual server image and a boot script to be associated with the virtual server configuration; b. retrieving periodically, by a virtual server manager, information specified by the policy; c. determining, by the virtual server manager responsive to the policy received from the user and the retrieved information, to instantiate an additional virtual server instance corresponding to the configuration; and d. transmitting, by the virtual server manager to a virtual hosting service, the instructions received from the user to instantiate the additional virtual server instance using the identified virtual server image and the boot script.