1. It's the easiest way to start interviewing with high quality companies
  2. You can see your salary before you interview
  3. Companies compete for you
  4. You get all your offers at once so you can make a choice knowing you've seen the best of what's out there.
    In a normal job search your offers come at different times so you often you have to make a decision about a particular offer before you know whether you'll get an offer you prefer later on.