After years of healthy growth, a perfect storm comprising the global recession, high unemployment, terrorism scares, flu-pandemic fears and continued economic uncertainty took a devastating toll on the U.S. travel industry in 2009.

Despite such difficulties, use of the online channel for researching, discussing and booking leisure and business travel has shown surprising resilience and will grow to constitute an even greater percentage of the total travel market in the post-recessionary environment.

While sales declined 6.7 percent in 2009, eMarketer projects that U.S. online leisure and unmanaged business travel sales growth will begin to accelerate this year, peaking at 7 percent in 2012, when sales will hit $105.4 billion.