Product Manager and Product Marketing
Question: "To what extent is a Product Manager responsible for Product Marketing?"
Answer: The first tenet in Blackblot's Product Manager's Toolkit® (PMTK) product management methodology is that the product management domain is comprised of the product planning and product marketing disciplines. The second tenet is that product management resides solely in the problem space.
The first tenet means that the true core strategic roles in product management are "Product Planner" and "Product Marketer". We need to focus on understanding these roles and realize that companies separate and/or combine these roles under different titles.
For example, in some companies the "Product Planner" is called a "Product Manager" and he/she mainly doing product planning (writing requirements, particularly market requirements in to an MRD). The Product Marketer is often called a Product Marketing Manager and that is a separate title and role that is assumed by a separate individual.
Some companies understand the linkage between product planning and product marketing so they seek a person with an undergraduate technical degree (to do product planning) and an MBA (to do product marketing), and call this person a "Product Manager".
In all cases in technology companies, "Product Manager" is just a label, a title given to a job container which holds two or more roles. Some companies add additional roles to the container titled "Product Manager", like a product owner role from Agile.
How to deal with the various role combinations under the "Product Manager" label and which roles to combine is a topic for a separate discussion.