Hey Richard,
Generally for eahc individual marketing effort, you should create a program for it. This means each email blast, webinar, nurture campaign...etc. should have their own programs. For high-level categorization you should be using campaign folders, so webinars would have their own folders, and eblasts would have their own. In this case it sounds like you want to partition the sales eblasts from your marketing eblasts, so having a campaign folder dedicated to them would probably be the best idea for you.