Excuse for possible ignorance here, but I fail to see any element of "Contest or Sweepstake" in this offer.
Originally Posted by Wikipedia
Under these laws sweepstakes became strictly "No purchase necessary to enter or win"
Since this deal is only open to MLB members residing outside of Japan, every participant is required to buy a ticket of transport to any of the two departing cities, alas, not necessarily limited to the organizer JL.