Heather Dougherty, senior Nielsen analyst and the report's author, attributed the agency's early advantage to the glut of suppliers for consumers to choose from on the Web. "The wide selection of travel suppliers drive the majority of travel shoppers to begin their research with agencies and meta-search providers before directly visiting a supplier," Dougherty said in a statement.
However, because about 50 percent of airline ticket sales and reservations were conducted exclusively online during the last six months, according to Nielsen, airline suppliers still have a stronger foothold in conversion rates.
"At that point, suppliers are in a strong position to capture a potential sale as consumers visit their sites to confirm pricing and frequent flyer benefits before making the final purchase," Dougherty stated.
Agencies, however, fared better in drawing visitors to their sites for price comparison shopping, destination searches, and multi-trip bookings, according to the survey.
Nielsen's quarterly travel benchmark survey also found that about 9 percent of prospective shoppers now start their search with the increasingly popular meta-search providers. Dougherty sees meta-search's growth as a boon to suppliers.
"The growth of travel meta-search players, such as Kayak and SideStep, provide suppliers with sales opportunities through side-by-side price comparisons with agencies," Dougherty said.
Of the airlines that did particularly well were Southwest Airlines, American Airlines, and Delta, which Nielsen ranked as the three most visited airline sites during April 2005.
Southwest led with 8.1 million unique Web surfers, compared to 5.7 million for American Airlines and 4.9 million for Delta. Southwest also converted the most "lookers into bookers" with a 14 percent visitor conversion rate, followed by Delta and American with 10 and 9 percent, respectively.
Online travel agencies attracted up to twice the number of visitors as airlines during April 2005, Nielsen found. Expedia led by drawing 16.3 million unique visitors to its site, with Travelocity and Orbitz ranking as the second and third most popular online travel agency with nearly 12 million each.
Expedia had a conversion rate of 5 percent, while Orbitz secured a rate of 4 percent and Travelocity came in at 3 percent.