Featured listings appear on the homepage and on a special section at the top of the Job listings and therefore get read by a lot more people than normal listings. Featured listings are particularly suited to Jobs that need maximum exposure, either because they are important/critical and hence need to get as many bids as possible to find the best expert for the Job or because niche skills are required.
To feature your Job listing, create a Job listing and select how long you would like to feature it for. You can also feature an existing Job listing by upgrading it from your PPH account.