The presentation is from 2011 so it is pretty dated. In particular the suggestion that you should use Blogger seems a bit outmoded.
The point Jeff Bullas makes well is that professional services are typically marketed best through relationships and referral: which is one of the things that social media does very well.
But you do need to start those conversations and have a place to bring people back to - and that is your blog.
Professional Services has Always Done Marketing Differently! Traditional marketing doesn’t work! Networking, giving & receiving Introductions, building relationships and being known as the subject matter “Experts” Does Work!