...broadly speaking, quite a lot.
We spend too much time maintaining communities rather than developing them. The former is to respond to the e-mails and notifications filling up your inbox, the latter is to initiatve things and foster relationships that develop a sense of community. Don't wait for things to happen, make them happen.
We mistake audiences, like those seen on Facebook, Twitter and blogs, for communities. Audiences are audiences. They interact with you. A community interacts with each other. They're two very different skills.
We don't integrate the community into the organizations. We bolt them on, or, worse, we outsource them. Don't do this.
We're not entirely sure what metrics to use.
We start communities for the wrong reasons, then get disappointed when they don't work.
We have unrealistic expectations of what communities can do.
We try to use the latest software instead of the best software for the task at hand.
We let ourselves be subservient to marketing, communications or technology.
We don't create enough content about the community. People want to know what other people like them are doing.
We're not always entirely sure what members really want. We too often resort to tangible incentives when the intangibles (fame, power, sense of achievement) usually work better.
We forget that we're competing against anything else people can do with their spare time, not other communities. Only communities with a strong common interest will survive.
We don't have enough good books about the topic. Those we have are often pretty poor.
We don't put together a set list of discussions, content and activities for the community at the beginning of each week/month.
Sometimes, we don't even have a strategy at all.
We don't promote and share our successes.
We don't learn from our mistakes, neither.
We keep using a marketing framework to develop a community. Build the site, promote the community, create some content and voila. We need an entirely different framework to make communities successful.
We let non-profits believe that a huge following of 1m is better than a strong community of 1000. Having had both, believe me - the latter is always better.
We don't know what skills make a great community manager. It's not being a good host, and certainly not being a social media expert. Too many people are recruited to roles that aren't right for them.
We use social media and communities interchangably. Some job descriptions even ask for both. They're two very different roles.
We don't know how to find good community managers, nor know how to spot bad community managers.
We do a bad job at setting realistic expectations and educating our employers/clients.
We're not experts at social psychology, community development, community psychology and sociology, but we should be.
We focus too much on moderation. Moderation is just one tiny slice of community management. What about strategy, growth, content, activities/events, relationship development?
We focus on the macro at the expense of the micro.
The good news is, we're improving at a faster speed than most other industries.