For example, imagine one of the requirements that marcom wants for the product is consistency with brand colors. I.e. the appearance or user interface of the product should contain colors that the brand logo contains. Consistency with brand colors helps strengthen prospective buyers' association of the colors with their perception of the product.
How would you measure such a thing? Consistency is a somewhat subjective attribute of a product. Gause and Weinberg, in Exploring Requirements (page 184), describe a way of measuring subjective attributes:
Another way of resolving measurability conflicts is simply to define measurement by authority. "What person or group can be given the authority to say 'yes' or 'no' about the satisfaction of this constraint?" Sometimes there is an official agency: "If the federal bank examiners will accept the auditability of this system, then we will be satisfied that the auditability constraint has been met." Other times there is an official process: "If the standards committee conducts a technical review and certifies this system, then the standards constraint will be met."If your product manager hasn't yet read Exploring Requirements, it's not too late.