I am new to this as well and have been following the board for a few months. My daughter did not receive a national scholarship but was contacted a week prior to the March board by the ROO at her #1 school asking if she was interested in a campus-based scholarship if the Nationals didn't get her the results she hoped for. She had her PMS interview at this school in December and at the time it was her #2 school. She instantly fell in love and it was quickly her #1 choice based on her interaction with the ROO.
She did not get the National but was just awarded a campus-based 3-year yesterday, just in time for commitment deadlines. She has also been informed she has a very high chance to be upgraded to a 3.5-year before the end of Fall 2014 term. This particular school offers 4 year room/board incentive to all scholarship cadets, regardless if it's a 3 or 4 year tuition scholarship. The most important thing I can say is to stay in contact with the ROO's at the school(s). My daughter was told that they were very impressed with her dedication and persistence. (a.k.a. Mom's nagging payed off big time!)
From all that I have read, it seems to be a rare occurrence to get a 3-year AD campus-based scholarship well in advance of getting to campus. This University has been amazing and understood our fear in committing to an extremely expensive private University with no guarantee of a scholarship award during freshman year.. They did everything they could to get us answers prior to the May 1 commitment date and she just signed off on her acceptance letter today.