Over the past several years whenever we were considering a Carnival cruise we were reminded about "Military" fares. But every time we checked the promotional fare of the day was always less than the Military fare - so it never got used and we never received Shareholder credit. Not apples to apples but on a booked 14 day Princess cruise we have $250 Military credit, $250 Shareholder credit and received a discounted fare along with OBC from our TA. We always check which works out better for us.