The share of U.S. travel booked online (i.e., online leisure/unmanaged business travel as a share of the total market) will increase to 40% by 2013, growing just one percentage point over five years. Yet despite the slowing overall growth trend, online penetration continues to vary significantly by segment. Only two segments were expected to book half or more of their sales online in 2011: air (50%) and rail (54%). At the other end of the spectrum, online bookings were projected to comprise only 11% of cruise and 5% of traditional vacation packages. Both segments rely heavily on traditional travel agencies for distribution. With the U.S. online market at a stage of maturity, in the short term, rail and hotel and lodging are the only segments expected to gain significant share in online penetration. By 2013, 56% of Amtrak's tickets will be booked on Amtrak.com, and one-third of hotel and lodging will be booked online, up from 29% in 2009. Related Link: PhoCusWright's U.S. Online Travel Overview Eleventh Edition