As you know, Lazy Sunday posts tend to be a bit off-topic.
Here's a thought-provoking post about non-active users, active users, and transactors from venture capitalist Fred Wilson. Maybe it will provoke some thoughts about your winery's Web-based community.
Active users tend to become transactors, so the question is, how to turn your non-active customers into more active ones? I think this may be one of the reasons that Twitter shows promise for some wineries.