The US is the global leader in online travel expenditures. Its leisure and non-corporate travel consumers will spend $122.4 billion by 2009, up from $64.9 billion last year, eMarketer projects in its new report, Online Travel Worldwide: A Mosaic of Separate Markets.

European travelers spent $35.5 billion online in 2005. And, the Asia-Pacific region, now one-quarter the size of the US market, reaped $15.9 billion in 2005, but is poised for quick growth in upcoming years.

What do these regions have in common? Demographic studies of travelers in the US, Europe and the Asia-Pacific region all show the emergence of an older generation of travelers, baby boomers (ages 45 to 60), who are healthy, adventurous and affluent, as well as Internet savvy, says Jeffrey Grau, eMarketer's senior analyst and author of the report. "Online travel distributors and marketers who pay attention to these customers and design travel offers matching their interests and needs will reap rewards," Mr. Grau says.

While the US is the world's largest and most mature travel market, growth is slowing down. In Europe, the UK, France and Germany are approaching maturity, although Southern and Eastern Europe still have untapped potential.

The four fastest-growing travel markets over the next four years are China, South Korea, India and Japan. China, with projected travel spending growth of 18.3% to 2010, will rise from seventh place to fourth place in personal and business travel spending among the world's 16 largest economies.

Related Link: Online Travel Worldwide: A Mosaic of Separate Markets