Travel planning and booking are among the most popular online activities and online travel sales are booming.

"Without question, the Internet has shaken up the status quo in the travel industry," says Jeffrey Grau, Senior Analyst at eMarketer and author of the Online Travel Worldwide report. "Traditional travel agencies are struggling to stay relevant, online travel agencies are trying to instill loyalty among their customers, travel search engines are the new upstarts, travel suppliers are flexing their muscles and global distribution systems are looking for ways to reverse their waning influence."

Only two things are certain in the travel industry today: the stakes are high and the competition is intense.

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