"Amazon already allows clients to add and remove different 'network instances' and 'block instances' from running virtual machines, thereby dynamically increasing or decreasing the I/O-resources available to a virtual machine," it states. "CloudSigma offers clients the ability to compose a flexible bundle from varying amounts of resources, similar to building a custom-made server out of different mixtures of resources such as CPUs, memory, and I/O devices."

But overall, "renting a fixed combination of cloud resources cannot and does not reflect the interests of clients," the paper adds.

In a RaaS cloud, customers would purchase "seed virtual machines" containing a baseline of resources as well as an "economic agent" for adding additional capacity, according to the paper. The agent will "will make decisions based on the current prices of those resources, the changing load the machine should handle, and the client's subjective valuation of those different resources at different points in time."

Cloud service providers' software would also incorporate economic agents to represent their own interests. Customers' agents could also negotiate with those controlled by other customers, who may have extra resource to sell.

Pricing for various resource types would be market-driven according to supply and demand. This notion could also be applied to SLAs (service level agreements), the researchers state: "When supply is insufficient for serving all clients, the provider can starve clients with lower-priority SLAs (e.g., only 90% availability) by raising the price of resources."