The ability to create custom audiences is huge! You can do really in-depth segmenting without having too many people involved. It takes more time than I would like but it works well enough that you get what you need out of it. If someone has less experience using this product they should definitely jump right into their first campaign setup rather then spend much time getting used to things. Once again custom audiences are big here as well. With our website we were never able to identify who was interested or not so now when creating an ad set my team knows exactly how those segments will react to different products/services. We also have been setting up campaigns which allows us to reach specific target groups that weren't being reached by other channels (like TV).