Consistent work with a community brings about good increase in interactivity. This is a graph, around two months since we started work on a community facebook fan page. Small weekly contests were held, but at the core of the activity was consistent 4-5 status updates daily.
The responses were studied noting the format, content and other parameters of the updates that got better response.

After some time a certain content, format was preferred. Based on that we soon saw a jump in engagement. This jump is consistent and also resulted in more responses to updates which are not according to the previously preferred format and content.