Sourcing for candidates is like hunting for moths: You can either track them down one at a time, or plug in a few light bulbs and net a couple hundred at once.

Or you can use both strategies at the same time.

While you're actively hunting for candidates, you can also work passively to attract new people to your talent community.

"Passively attracting" is the idea behind a candidate pipeline, which is the sum of all the light bulbs you set up to draw fresh candidates into your net. Here are a few pipeline-building strategies:

1. Send a quarterly e-newsletter or job alert. The people you send it to will forward it to their peers, and you’ll receive subscription requests with the e-mail addresses of new candidates.

2. Build a profile page on social networking sites. Choose from the major players (such as LinkedIn, Spoke, Facebook, etc.) that are populated with the type of people with whom you'd like to connect.

3. Use your Web site as a portal to your pipeline. Make it easy for candidates to contact you if they’re interested in your jobs, your services or subscribing to your newsletter.

4. Write articles that will appear in print or online. Every market or skill set has an association, interest group or blog community. And they’re all are hungry for news, insight and opinion.

5. Post and cross-post your jobs. Try both the big guys like CareerBuilder and niche-market job boards. And don’t forget free sites like Cragslist.

6. Experiment with paid search engine rankings or sponsored links. Google advertising can draw lots of visitors to your Web site, and by extension, your pipeline.