There seems to be a lot of confusion in this thread!
See here for details:
RPGA DM Rewards program
The adventure is a reward to all members of the RPGA DM Rewards program. The new system sends out one reward (this one) to everyone who renews/updates their contact information in the DCI system and is a member of the RPGA DM program, each year. On two other occasions, RPGA DMs who run and report five RPGA adventures in a six month period will receive other rewards (I think the first of
those is slated to be a dungeon tile of a ship.
Under the previous rewards schemes, rewards were sent world-wide. I'm expecting to receive this mailing in the UK once it gets across the pond, and I hope I won't be disappointed!