As a rule most hiring managers do not understand recruiting. They think all we do is look at Monster or Hotjobs (which was just bought by monster) or the other databases and find people with no problems. They do not understand the amount of work that goes into the sourcing part of recruiting. One way I have found that has helped me educate the hiring manager, is to arrange sourcing sessions with them. Make an appointment to meet with them and talk about the opening and source. You will be amazed at how different they will think once they sit with you for 30 minutes and you source. I have done it many times and they come away with a new appreciation and even admiration for what we do. You will find it strengthens your relationship with the hiring manager and by default will make recruiting easier.