Recruiters get
annoyed by small
things that you may not think of — like whether or not the text on your cover letter and resume is the same font and size (it should be), if your margins are off (makes it tricky for us to print), or to whom you've addressed the cover letter (it should be the
recruiter's name, not «sir,» «madam,» or «to whom it may concern».
When you're on the job hunt, the last
thing you want to do is
annoy hiring managers, interviewers,
recruiters, and so on.