Effective monitoring is essential for the security of cloud systems. Although many monitoring tools exist in the cloud domain, there is little guidance on how to deploy monitors to make the most of collected monitor data and increase the chances of detecting security breaches. We introduce an actor-centric, asset-based cloud monitor deployment model that enables practitioners to reason about monitor deployment in terms of the security of their cloud assets. We define an actor model that consolidates several roles in the literature to three roles motivated by security. We then develop an architectural model that identifies the assets that can be owned by each actor, and use it to drive an asset-based cloud threat model. Using our threat model, we describe how a cloud practitioner can reason about monitor deployment to more efficiently deploy monitors and increase its chances of detecting intrusions.