Nearly every question is an opportunity to create a new owner.
If you ask your community manager to host a weekly discussion on a topic, the best response s/he can give is: “great idea, what do you need from me to make it happen?”.
Your question was a contribution. The community manager turned your contribution into something you own. Now your ego is invested in the success of both the weekly discussion and the community as a whole. You’re a co-owner. You’re going to work hard to turn your idea into reality. Your ego is invested in your idea.
Nearly every question, comment and complaint is an opportunity for you, as community manager, to create a new co-owner.
If someone points out a problem, do they want to help fix it? If someone points out something good, do they want to make it better? If someone is passionate about a topic, do they want to have their own forum/ask-an-expert area on the website?
If you want more activity, it’s not a bad strategy to cultivate more co-owners.