Crystal Cruises has launched an agent incentive to mark its return to Alaska in five years. In the incentive, the cruise line will give an Amazon Kindle to all agents that make an Alaska booking through December. To encourage bookings, Crystal is offering free British Airways World Travellers Plus flights from London on bookings made before 31 January 2010. These are available for 2011 Alaskan sailings in May and June. In addition, free BA return flights are available for the August and September voyages.