I've said it before that most social networking tools, including Twitter, are after-market tools and not commercial marketing devices. 
 

  I've been on MySpace and other sites for years now, and have had less than a bakers' dozen contacts in that period and only one that was a new client.  The rest have been other professionals looking to join our notary network, or seeking to provide research services, or pumping us for free advice on local markets. 

  Make it an available option to your clients.  Link it on your website.  It may not be a great tool today, but it is a two-way tool that can bring information to you.  Use the friend-finder features, subscribe to realtor Tweets to stay abreast of conditions in your area, and continue to connect.  In another ten years, it might be an indispesible tool and a value-added asset to your service (which might be valuable if you ever choose to sell your business...kind of a client "rolodex" that's easier to use and with more options).