Great communities inspire great conversations. Online communities are no different.

Fred Wilson once said in his blog, “modern [online] community building isn’t easy, but if there is one thing the Internet has taught me over the past 15 years, large engaged communities are incredibly powerful things, both commercially and socially. Building them is important and ultimately very valuable work.”

One of the definitions of the word “community” is “body of persons of common and especially professional interests scattered through a large society.”

The Internet allows people with common interests, be it Mac enthusiasts or IT people, come together even if they are “scattered through a large society.” People always want to belong to some kind of community where they can share their thoughts, opinions and interests with others.

Every business has the opportunity to take advantage of this phenomenon and unite their customers and fans in an online community with a common interest – their brand.

Many brands build online communities hoping that it would be an easier way to talk to their customers. They keep creating and pushing content out to their fans, failing to realize that many of them join an online community not because they want to listen to brands, but rather talk and share their experiences with each other.

Online communities can generate valuable content for your brand if you would just let your fans talk. Their opinions might not always be positive, but the fact that your fans talk about you already means they are interested in your business. And even negative feedback can be turned into a learning experience. Just make sure to address those comments in a timely manner (watch for a blog post on crisis management soon).

Sephora’s “Beauty Talk” online community on the website had exactly that result: “we realized that…clients were not only trying to talk with us – they were trying to talk with each other. And they were actually engaging in ways we had no idea they would,” said the VP of interactive media at Sephora.

A strong online community, where people have the freedom to express their opinions and know they are being heard, nurtures community leaders that can become brand advocates both online and offline.

Facebook is a great platform for your business to start building online communities. It is important to give your customers a voice, even though it might be uncomfortable at first. Ask questions, encourage conversations, monitor and listen. Your fans have a lot to say about your brand, don’t limit their ability to interact with each other and with you.

Sometimes old dogs can learn new tricks.

In fact, you don’t have to be a fan of that old Schnauzer the Recording Academy to be completely blown away by the elegant and compelling social media campaign it’s created in the run-up to the 52nd Annual Grammy Awards — it’s a virtual doggy ballet, in fact.

Rather than explicitly spreading the Grammys’ in-house branding, the Academy has embraced the notion of user generated content as a reflection of artist buzz.

To exploit this concept, Grammy marketers have created a dedicated site, wereallfans.com (or “we’re all fans” — the contraction is a bit awkward), that collects fan-created YouTube videos, Flickr photos and tweets related to the top nominees and places them in a beautifully miasmic visualizer. It might give you motion sickness, but it’s really cool.

Best of all, you can add to the party by clicking on “join the conversation” in the lower-left corner. Log in to your Twitter, Flickr or YouTube and whatever you post will float off into the fray. Or you can create your own fan portrait. Click on the “fanbuzz visualizer” for a slightly less vertiginous interactive graph showing each artist’s buzz.

Meanwhile, over at Grammy.com, the site’s been loaded up with social features: Facebook and Twitter feeds, community blogging and a free iPhone app, to name a few of the bells and whistles.

For anyone with the money to spend on a massive social media campaign, this is pretty much how it’s done.

Oh yeah, and: Leonard Cohen FTW!

Further reading: Billboard.biz interviews the marketers behind the campaign.