Hi Kate, good points here about narrowing the point of focus and really defining the ideal client - thanks for sharing.
I will say though that I disagree with his take on participating in industry forums - and as an
SEO I think he missed an important point about the value of participating in forums [of course I'm biased

] But I point this out because an industry forum like VAF is going to be 1,000x more optimized than say, your average VA business website - by simple volume of keyword density if nothing else. And then when you couple that with the kind of active
SEO and promotion that's done for a site like VAF the search returns become even more intensive and cast a much wider net.
With that in mind, the chances of a client searching for a VA via specific keywords in Google and landing on your thread, blog, profile or group page on a VA online community are so much greater than that client landing on your VA business site for the same keywords.
We know that clients are landing on this site in particular, and seeing conversations that resonate with them, they get in touch with the VA - locating their VA business site via their profile page or the link in their signature.
The question then really is - is your ideal client using Google to search for a virtual assistant? [And of course they very well may be] Which leads to the next question - when you DO participate in online communities are you treating it as an important part of your marketing and networking agenda?
Potential clients will find you through Google searches, here and on other social networking sites. That's when good client consultation practices become very important - to help identify the potential for an ideal working relationship with clients who do come to you that way.