Many times, the candidate you really, really want (the one who is that perfect fit for the job) is already happily employed and not actively looking for a job. But that doesn’t mean she is off limits; it simply means she is a passive candidate and must be recruited differently than an active one.

Active job seekers are likely to pursue you, respond to your job ads, attend career fairs and send resumes your way. Passive candidates, on the other hand, are busy working at their current job --  so you have to pursue them.

Related: How to Hire Someone Aligned With the Company's Mission

Here are six tips for finding and recruiting the passive candidate who may be perfect for your next hard-to-fill position:

1. Revisit your resume files. When you are searching to fill an open position, don’t forget to consult your files of past applicants. You likely have hundreds of resumes of people who have applied for other jobs at your organization at other times. Maybe the ideal person for the new job applied for another post three years ago. While he may be ensconced elsewhere at the moment, it might be worth contacting him about your current needs.

2. Blog about hot industry topics. Even if top-notch candidates are not currently seeking an opportunity, stay on their radar by publishing an informative blog focusing on hot-button topics in the relevant industry. Rather than writing about careers, blog about issues that matter to people working in a particular field, the kinds of posts that are passed along to others and that go viral. This way, your company’s name and reputation will be familiar to the passive candidates you approach.

Related: How to Hire Without Spending a Fortune. (Hint: Use Social Media.)

3. Listen to what motivates passive candidates. When approaching passive candidates, start by simply opening the conversation. Don’t be pushy and take time to listen to what the candidate really values. Many times, it’s more than just money that draws a person away from one job to another.

A recent survey released by my company, Glassdoor, found that when it comes to recruiting software engineers, 52 percent will accept less money to work at a company with a great culture: This means your firm’s people may matter more than the budget. Pay attention to the needs and interests of candidates, determine what will motivate them and look for ways to offer what they need.

4. Meet in person. While your recruitment of passive candidates will likely start online, try to follow up with in-person meetings. Just having coffee or lunch with someone can go a long way toward building a relationship. Don’t be overly aggressive; position yourself as an expert in the industry rather than a recruiter. If you can provide valuable information and a valuable network, in-demand candidates will want to stay in touch with you.

5. Ensure privacy. Many passive candidates don’t want to actively look for jobs because they don’t want their current employer to know they are looking. If you request a resume or other application information, be careful to keep the information and your conversations confidential.

6. Respond to reviews of your company. Many candidates visit job sites to learn about companies before they’re ready to make a career move. Reviews of companies can be found on job sites such as Glassdoor and others. Be an active participant in the conversation happening about your company. Post replies to a review about your organization; share positive feedback on the firm's careers page and social channels so that everyone knows your company values what employees say.

Related: Onboarding Essentials: What Really Matters to New Employees (Infographic)