My "50% bonus" posted today. I flew from HVN to PHL which is 157 base miles. As an EXP, I got the 500 mile minimum for the flight, so with my standard AA bonus, I got 1000 miles for the flight. However, the "50% bonus" was 50% of 157 or a whopping 79 extra miles. Thanks, AA.

Oh, but wait - the terms of the promo say (emphasis mine):

AAdvantage 50% mileage bonus offer is valid for travel on US Airways, US Airways Express and US Airways Shuttle operated flights (includes codeshare flights marketed by American Airlines) for travel systemwide from January 13, 2014, through March 2, 2014. Offer applies to travel on purchased, published fare tickets that are eligible to earn AAdvantage miles. Bonus miles do not count toward elite status qualification or AAdvantage Million Miler status. 50% bonus miles will be calculated at 50% of the base miles earned or, if applicable, the minimum mileage guarantee. Registration prior to midnight CT on March 2, 2014, is required. Travel flown prior to registration will be eligible for the bonus. Bonus miles will be awarded within 3-4 weeks after the promotion period has ended.

Am I reading this incorrectly, or should I have gotten a bonus of 250 miles total (50% of 500 minimum)?