Continuity programs give you stable and predictable income. This might help convince people to join.
Offer parts of what you provide in your continuity program (webinar, article, one-day forum access) for non-members for a one-time access fee. You should price the single access fee to make your monthly fee seem very attractive. So if your monthly fee is $79, you might want to offer a single access for a one-time webinar (that you would get for free weekly as a member) at $49.