Whenever I talk to web businesses, there is a topic that comes up time and time again: social networks. Love them or loath them, 2009 really was the year social networking went mainstream. The pessimists will have you believe this is fuelled by our celebrity-obsessed culture and almost narcissistic fascination with ego searches. However, social networking is bigger than Stephen Fry’s breakfast and hopefully by the end of this article you will see how you can use social networking sites like Twitter to bring some real business benefit.Twitter, the biggest phenomenon of the genre, operates around the open questions “What's happening?”, and you only have 140 characters to answer. Looking at my own tweets (@benjamindyer) I admit, many of them are completely pointless. I see something I like or dislike and I tweet about it. However, looking at the bigger picture, this conscious stream of information turns Twitter into a surprisingly powerful tool, especially for business.There are lots of companies doing some quite incredible things. Dell recently announced it has made nearly $6.5m in sales directly from its Twitter presence and has over 1.5m followers. Ford too has a great set of Twitter streams and US cable company Comcast is rewriting the customer service manual with its exploits on Twitter.So we have established that big companies are setting up their stalls within these social networks. Where these businesses are throwing vast sums at establishing a presence we should all be able to learn from their experience, regardless of the size of our business.First, check your customer demographics: Find out if they use social networks, and if so which ones? Chances are they are on Facebook, but don't forget Twitter is key to some and there’s Linkedin and FriendFeed too. Ask customers what they use.Next, I believe it is also important to do as much listening as talking, and this is where a lot of companies come unstuck. Use the search engine on each social networking site to find who is talking about your company. The Twitter search is incredibly powerful and can really give some amazing insight into your brand, products and customers.Also extend your searches to include competitors and anyone respected in your sector. Track what is said about the products or services they supply and what they are promoting. What can you learn?Remember that the heart of social networking is engagement. If you find someone talking about you or your products, then get chatting. Ask questions and listen to the feedback. This is an incredibly empowering process for your customers. No matter how big or small your company, we all like to feel that someone cares.A great example of fantastic engagement is the US cable company Comcast, a brand that has been synonymous with poor customer service for years. However Comcast in 2009 became a completely different animal.One change has been to embrace social networking. Comcast is on all major social media sites like Twitter, FriendFeed, Facebook, etc. This presence gives it direct access to its users. Searching for examples returned hundreds of satisfied customers and barely any dissatisfied ones. Two years ago this would have been inconceivable.One great example comes from Comcast customer @cc_chapman:"Last night I made a snide remark about the lackluster quality of my HD picture on Comcast during the Celtics game. Comcast saw that and tweeted me back minutes later. This morning I got a call from their service center. This afternoon someone came out. Now my HDTV rocks! THAT my friends is customer service and how it should work all the time."Engaging closely is one thing, but remember that a person’s online social space must be respected: Be smart and polite. Don’t go butting into someone’s conversation with a blatant plug. This is a fast track to achieving the exact opposite result and being blocked. Far better to offer advice that’s relevant and of interest to your audience.While most people now have some sort of online presence, the biggest complaint I hear is, “I haven’t got enough time.” It’s understandable and depending on your business and the social networks you intend to have a presence on, you’re bound to drop some plates. However, there are free tools that can really help. A good one is the brilliant Tweetdeck. Tweetdeck connects up to a number of social networks (Twitter, MySpace, Linkedin, Facebook), its power comes in the ability to define searches or groups of people to watch. These searches are organised into columns that aggregate the data.Social networks are not just the preserve of those interested in Britney’s personal life, it’s a mine of information. If you’re not using it I can guarantee your customers are already talking about you. And your competitors are probably talking to them.So, what are you doing?