Or at least on cordial terms.
While we, as technical writers, generally spend most of our face-time with engineers, programmers, and developers, keeping a good relationship with the marketing department is also imperative, especially when creating some of the newer and more effective documentation types.
Marketing and documentation should be symbiotic. Sales associates will often use help files, requirements, specifications, and tutorials as a way of demonstrating how easy their product is to learn and use. If you are posting any of the information you create publicly on the web, marketing will want (and, really needs) a say in the look and feel so that all the products online have a similar look and feel.
Technical communicators can be good translators between marketing and development as well — quite frankly, sometimes development people are more likely to feel that the technical communicator understands them better than the “marketing wonk,” especially if the tech writer has been working closely with them for a while. For this to work, however, it’s imperative that the tech writer maintain sovereignty and not be seen as another marketing arm by development — or as a development arm by marketing. Tightrope walking – another meaning for the TW acronym!