Enhanced descriptions from Syndetics:

There are three major categories of communication within a Project Communication Plan: mandatory, informational, and marketing. Mandatory and informational communication are, typically, well addressed by project managers; it is simple to understand and to enact. The third element, the marketing communication however is often neglected, to the detriment of the project and its likely achievement of success. The accumulated wisdom of project management provides the basis for winning the minds, or at least a reasonable level of attention, of all the stakeholders. Marketing communication is designed to sell to stakeholders the value and benefits of the project. To get them on board in a supportive and committed way to help you help your project to be successful. There is a misconception that most projects have no requirements for this type of communication. This leads to a lack of focus in a critical area and, when you are project number 82 in a portfolio of 200, then a degree of invisibility and lack of importance. So project managers should, at the very least, learn how to 'market' their projects in an effective manner. But beyond this there is then project branding. Branding a project is achieved through creating a project personality with which stakeholders can have a relationship and therefore an emotional attachment. This personality or identity is known as the project brand and it is key to maximising buy-in and support from the widest range of stakeholders. If marketing communication wins the minds of these stakeholders then project branding should win their hearts as well.