不是每个都有的.
这里是terms
Promotional Terms and Conditions
Offer is valid for recipients of this email only. Only AAdvantage®
members who receive this email will be eligible to earn AAdvantage®
bonus miles. To qualify, you must have referred friends between May 25, 2010
and August 31, 2010, and referred friends must have enrolled in the
AAdvantage program as new members and completed an eligible activity (travel
on American Airlines, American Eagle or the AmericanConnection®
carrier, get