Any professional whose work is visible on the Net will become part of the conversation that establishes reputation and creates opportunity. The blog is an active résumé that enables you to participate -- by proxy -- in that conversation.
What an active résumé should include will vary by profession and according to personal inclination. For a musician, a couple of complete tracks from each CD. For a home renovator, photos and write-ups of some completed projects -- and for extra credit, video walkthroughs. For a programmer, links to those of your applications, tools, or specifications that touch the public domain.
Here's the bottom line. What Alf calls "collaborative filtering and recommendation networks" will rival -- and my guess is, largely supplant -- conventional marketing and promotion. But if those networks can't find you, they won't be able to help you.
Do I really need to add anything? Perhaps a few points…
- (Your own) Content matters: put your thoughts and ideas on the web, because it's easier to notice them there and people still need you to implement them (well, at least until brain scanning gets perfected).
- Make it easy to find you: this goes from activities such as joining online networking sites that make sense for you to making sure that your content is easily visible to search engines.
- Participate in the conversation: you have to be very very good to be able to just shout from a mountain top and have people turn and listen. Post on other sites, leave comments, and of course link unto others.
These three items will make you part of a larger community, which in turn can (will!) lead to opportunities.