I’ve recently been thinking about the long-term effectiveness of job boards like Monster and TheLadders.

I am impressed with the way these two job boards have grown to dominate their marketplace. It took a lot of ingenuity, hard work, and marketing savvy. And ultimately, they both do what they claim to do: match up companies and workers. Staffing professionals – especially those in big companies – aren’t doing their jobs if they don’t use such job boards as a baseline research tool.

But here’s my concern: job boards are set up to provide a recruiter with a lot of matches, not great candidates. In the end, they are a sophisticated version of classified ads. They have broader reach than the hometown newspaper, and they can be used by employers and potential employees alike, but they still follow the “job description/apply here if you’re interested” model.

As any recruiter or job seeker can tell you, this is not the way most people find jobs. Most job placements come about informally, through referrals. And why shouldn’t they? Start with 1000 applicants on the one hand and a referral from a friend or employee you really trust – which is more likely to produce a good employee in a short amount of time? It’s no wonder that many companies provide small bonuses for employees who refer friends that end up getting hired.

For really important positions, then (and maybe some not-so-important ones), the recruiting path should primarily be one of expanding referral networks. That’s why I’ve said that LinkedIn can be so helpful for today’s social-savvy recruiter: it expands a referral network the way Monster expanded the classified jobs section of the newspaper.

The difference, of course, is that referrals are a better way of landing a top candidate. Before they show up for an interview, you’ve been able to hear about them from all kinds of people you trust (and people they trust, and so on).

Does this mean that you can never recruit a top candidate from a Monster? No, of course not. I know plenty of recruiters who have, and I encourage employers and job seekers to use it. But I also advise spending more time expanding referral networks through LinkedIn and other networking opportunities.

Do you think I’m right? Wrong? Am I missing something? Join the conversation below.