Great article Peter.
I will re-iterate what has been mentioned above. Social media is a great way to stay in front of people. At SiteScapes, where I work, we have added a FB feed to our home page. Our aim is to let our customers know we are busy and keep them up to date with projects we are especially proud of. This is a new undertaking and we are still gauging the effectiveness of this endeavor.
Like Peter’s article mentioned, these tools, provided by social media sites are very inexpensive and often snap into existing web sites and profiles. It is very easy to integrate a FB “like” button and I am excited about the integration capabilities of FB’s new social commenting system.