The first charm is the Airship Charm, which will deliver 25 tourists to your resort’s airstrip. It can be send to friends as a free gift on the game’s free gifts page, or you can purchase one for use on your resort from the store for 9 Facebook Credits.
The other charm, the Pirate Ship Charm will deliver 100 tourists to your island’s dock via a pirate ship. It is only available to purchase from the Charms section of the game’s store, and doing so will set you back 29 Facebook Credits, or around $3.
If you need a quick boost in tourists, to help add some extra coins to your pocket, make sure to ask your friends (nicely) to send you some Airship Charms in the game. Send some out yourself by heading over to the game’s page.