The vast majority - 88 percent - of U.S. online users resorted to the internet to purchase or plan their summer vacations this year, writes iMedia, citing Claria's Feedback Research, which collected data in the three months (April through June) prior to summer vacation travel. Some 61 percent of online consumers going on vacation also purchased or planned to purchase airline tickets online - 12 percentage points more than last year.

Price comparison is apparently the greatest driver of the online trend. Some 53 percent of respondents said they would travel with the company that offered the lowest price. And 78 percent of those who purchased travel online said they chose the sites based on price; only 28 percent made their selection because of frequent flier or other loyalty programs.

Also, site hopping is common. More than 60 percent of those who viewed Hotwire.com, for example, also viewed Orbitz.com, Expedia.com, or Travelocity.com. More than half of those who viewed Delta.com, United.com or Southwest.com also viewed Orbitz.com.