What tips do you have for building up your communities on social media sites?

My first piece of advice is to prioritize your efforts. Many people hear that they need to be on FB, Twitter and Linkedin and often spend too much time trying to develop a presence on all three or whatever other social media site is popular that week. Identify which site is the most important to have a presence on and figure out what is the best way to add value to your following through that site. It might be by creating content, recommending content, fostering discussions or a combination of everything. Make sure that you provide the opportunity to follow, connect or join your group in every interaction you have with them. Our organization was able to build a group membership of over 50,000 in Linkedin groups by creating high quality, thought provoking discussions and inviting people to participate in those expert discussions....we would promote those discussions in every communication we had within the organization (mass emails, 1:1 emails, LI connections, etc). Those numbers can add up quickly when there is a concerted effort by the organization to promote one active discussion at a time...

I think the most important factor is to BUILD RELATIONSHIPS! In an online world we tend to think of "communities" as virtual masses rather than groups of individuals, each with their own unique personality, needs, and wants. I try to build real relationships, then the communities follow.

customers are interested in your services if what you have to share is relevant and interesting. Social media can help you both keep in touch with your customers on a regular basis (maintaining a point of contact with them at all times) and determine who your actual core clientele are by getting feedback from your existing group, which will in turn grow the group!

First, put your Twitter, Facebook, etc. links on every email as well as advertisement.

Second, add friends and colleagues and invite people to your social media outlets. Follow their feeds as well.

Lastly, make sure you contribute on all fronts. You cannot expect people to be following a twitter feed that hasn't had a comment in over a week.

An optional thing you can do is offer small incentives from someone reading your Twitter or Facebook. For example, a discount for service.

Join LinkedIn groups.
There are hundreds of thousands and once you join groups, become an active member. You can join as many as 50 groups. Participate in the groups, don't just observe; which brings me to my other suggestion:

Ask and answer questions.
Thoughtful questions and useful answers add to your street creds. The best ones give people a reason to look at your LinkedIn profile. Answering questions in your field establishes your expertise, raises visibility, and builds social capital with your network. Ask a question; people sincerely want to help, so tap into your peers’ expertise with open-ended questions.

1. Focus on engaging the community members as human beings.If you participate as a helpful, engaging, and responsive member, the masses will naturally take interest in your business.

2. Take some time to actually visualize the members as dinner guests. This should prompt you to be a good host and to remember your table manners.

3. Consider the groups needs and place them above your deep seeded desire to relay a marketing message.

4.Provide content in conversational English (not the BS of business lingo). Make sure that is useful and entertaining to community members.

5. Provide passive opt-in opportunities for the community to learn more.

I use the same strategy employed here on Focus. I constantly ask questions.
My focus is on content so my updates are loaded with content I believe will be useful to my audience or community.
I keep in mind the basic real world networking question of "how can I help you?" With the question in mind I produce content meant to aid my community is some fashion.
If I find content created by someone else that I believe would benefit my community I pass that information along with credit to the creator.
With each status update I typically notice at least an increase of one in my community. I suspect I would probably grow the community more if I updated my social networks more often.

Here are 10 suggestions:

1.) Be realistic about where your customers / prospects are. If you are a B2B company, than Facebook may not be your primary social outpost. A LinkedIn group may be better.

2.) Create a manageable number of social outposts. You don't want to create the false expectation of engagement. If you have a dedicated social media resource, great. Try multiple outposts, and participate actively in each. If you have a shared resource, then pick out a couple of sites -- those that will reach the right people -- and engage in them meaningfully.

3.) Social media shouldn't replace traditional marketing, it should extend/complement it.

4.) Be patient. You have to earn your stripes. Trying to game the system will backfire. Always does.

5.) Good content begets good reputation. Add value wherever you are.

6.) Tailor your voice to the community. Your Facebook Fans expect a different version of you than, say, your internal user group, who, in turn, expect a different version of you than your SlideShare following.

7.) Have realistic expectations: one single tweet isn't going to sell out an event.

8.) Speed is the currency of the social Web. Respond immediately.

9.) Create a publishing waterfall: when you create content, know how that content will cascade throughout your social distribution channels. Consider using services like Ping.fm to publish to multiple outposts at once.

10.) Be sure to get your customer support team involved, especially on Twitter. Support is becoming the killer app of the social Web.

Joe Chernov
Director of Content
Eloqua

see answer above.

I think posting queries/answers with your email address on any discussion in forums such as linkedin makes you get more no of invitations.