What is an AI agent in marketing?

The distinction that matters in a marketing team is not technical but operational: an assistant saves you sentences; an agent saves you a task-sized job. That changes the cost math (the expensive part becomes supervision, not the tool) and demands what almost nobody writes down: governance rules about what it may publish alone and what it may not.

A complete operating example, with the system, costs and rules in plain sight, is documented in the y8y case: a trilingual publication run by one person with agents. The lab's general framework, in AI systems.