1. A method for providing resources in a cloud computing environment, comprising: receiving a request from a first user for one or more standby reservations of virtual machines associated with a first virtual machine pool corresponding to the first user; assigning one or more preemptible virtual machines to a second virtual machine pool corresponding to a second user; performing one or more tasks for the second virtual machine pool using the assigned preemptible virtual machines; determining that a load-based threshold for conversion of at least one standby reservation for the first virtual machine pool is satisfied; selecting at least one preemptible virtual machine assigned to the second virtual machine pool for preemption based on at least one of a bid price associated with the second virtual machine pool and a length of time for performing a task on a preemptible virtual machine; stopping performance of tasks on the at least one selected virtual machine; and assigning the at least one selected virtual machine to the first virtual machine pool as a dedicated virtual machine.