Answer: Instead of angling for a meeting invitation, go back to square one and have a basic discussion with your boss about goals and expectations. Lacking experience in marketing, he probably has no conception of your potential contributions.
To clearly communicate your value, draft a projected work plan and review it with him. Without using marketing jargon, describe how your proposed steps can help the company reach important milestones.
Once he has signed off on your goals, explain how involvement in the planning process will be critical to accomplishing them. Then suggest that you attend the next strategy session.
On the other hand, if your boss seems to have absolutely no interest in using the full range of your talents, then your planning may need to include another career move.
Have you recently gotten a new manager? Here are some helpful tips: Strategies for Surviving a New Boss.