If you are meeting so-called passive candidates, they may have been provided by headhunters. These people have good jobs and are not yet necessarily convinced that they should make a move. If you feel you have a strong candidate, you need to switch into sales mode. That means you must tell them why the grass is greener on your side of the fence, compared to their present job. If you manage this, the candidate will leave convinced that your company is offering a great opportunity. Always remember that hiring is also a selling activity.