All personnel in these functional areas are required to work cooperatively and consistently, conscious that decisions made by any of them can send messages that ultimately influence customers (Smith 1996). This is also consistent with Petrison and Wang's (1996) proposition that IMC could be interpreted in two distinct ways: "planning integration" and "executional integration." Planning integration advocates that to maximize efficiency and effectiveness, marketers need to coordinate all marketing activities to ensure that they are in line with the overall strategy of the product and brand (vertical), whereas executional integration is associated with consistency between communication messages (horizontal).