1. Companies confuse communities with marketing
An online community is primarily focused with building the relationship between your business and your customer. This is not a marketing function. Notice I said "customer". THEY ALREADY MADE THE PURCHASE. A community should be working towards helping the customer get more out of their purchase, thereby strengthening their loyalty and creating a positive frame of reference for future purchases. While this can be lumped into the category of "brand building", to equate it to the same functional level as newsletters and email campaigns is a fatal mistake.
2. Companies create communities for "support"
Many online communities are created as a support mechanism for a company's customers. Rather than directing customers to a phone or email address they are guided to a community to post their questions and problems. This is just fine when the questions are being answered by company staff and the forum (rather than community) is grown as a knowledge base for the users. Where this falls apart is when an expectation is placed that other community members will answer the support questions for the company, leaving the company to get involved only when they deem necessary. Do you really want customers who are not as familiar with your products and services providing unmanaged and possibly uninformed guidance as to how to use them? This is where the separation of a support forum and a user community have their greatest strength. One solves problems, the other provides ideas and inspiration.
3. Community Moderation is not an intern-level skill
So many companies take a newly minted marketing person, first level help desk, or worse yet, temporary intern and place them in charge of their community. A community moderator needs to be informed about the company, products, and services, a strong communicator, troubleshooter, researcher, and facilitator. A community moderator is not someone who signs in each day just to check and see if there are new posts. If you place a moderator in a community who has a purely responsive role rather than a proactive one, take heart that the community will not be something you have to worry about for long (since no one will be using it.)
4. Communities take work
Reasons three and four compliment each other. The success of the community is dependent on the moderator building an environment that not only draws in new members, but keeps existing members coming back for more. That means creating new content, encouraging discussion and interaction between members, and promoting the community as a valuable resource to the company user base. A moderator who sits back on their heels and expects things to happen on their own will be sitting by themselves. Communities are living, breathing entities and need to be handled as such.
5. A blog with a comments section is NOT a community
I was speaking with a gentleman recently about how his company was handling engaging his user community and his response, well, it was sad. "We've got that covered. We write a blog post about things every couple of weeks and it's got a comments section on every post, so if people want to post and ask questions they can do it right there!" The list of reasons why this is wrong is too long to mention in this post alone. Suffice it to say if your company thinks the "company blog" is going to build and strengthen your user community and build engagement, you've got a surprise in store for you.
6. Communities are moderated, not controlled
To build a strong community there has to be a degree of trust with the community members. Here's a common position companies take: no posts to the community may go public without review from the marketing team due to concern for negative brand impact. If these are the rules of your community, please make sure you turn off the lights when you leave. In an effective community, yes, negative things will be said. Yes, someone might say they don't like what you have done, or things were better the old way, or why do you have to keep changing things, etc. These are not the difference makers to your brand in your community. The difference makers are HOW YOU RESPOND. A customer comes to a community for either the opportunity to get more from what they have or to complain about what they got. Each gives you a chance to learn, respond, and set the tone about your company to the other members of the community.
7. Twitter is not a community
Twitter is a ping-pong board. It is not the place to engage with your customers. If you want to disseminate content from your community, then by all means Twitter is fine as part of an overall strategy. Just don't kid yourself you are building a relationship 140 characters at a time. "I love these guys and I'm a loyal customer because I can talk to them on Twitter," was said by no one, ever.
Communities are powered by people, not technology. The tech will change but the need for customers to feel comfortable, satisfied, engaged, and understood will be a constant. Keep that in mind when building your communities and your chances of success have just gone up.