Members of your community do a lot. You rely on them to make the community a success. You can influence the direction of your community, you can influence its content and you even have an influence over the type of members you want in the community. However, when it comes down to whether your community is going to be successful, your members are all that matter. You need to not only attract members that will help your community grow and continue to develop, but you need to keep them. You can do this by making sure they feel special.
Community Spark has turned out to be a real gem in explaining how community building works and why community management is such an art.
The best thing a company can do to its community management efforts is to put a passionate and dedicated person in charge, and give them the *time* to do their job well.