Within online travel, Car Rental agencies don’t attract as much attention as Online Travel Agencies, Hotel Chains, and Airlines. In terms of online activity, however, car rental sites generate significant audiences and upwards of a hundred million dollars in reservations each month. Compete compared the audiences and reservation performance of the major suppliers to see how they stacked up.

Over the past 13 months the top rental car websites have averaged 1.1 million U.S. unique visitors per month. The largest site, Enterprise.com, averages 2.1 million prospects per month. Chasing Enterprise are Hertz, Budget, and Avis, all of which average just over a million monthly visitors. In a sign of the impact of a slowing economy, year over year site traffic is down an average of 12% across the seven largest sites.

Reservation levels at Car Rental agency sites – which do not typically require a credit card or upfront payment – are very high. 17.5% of visitors to Dollar.com complete a reservation, making it the best-in-class converting site. Over the past 13 months, the average rental car reservation rate has been 13.6%. The laggards of the group, Budget and Hertz, still maintain respectable 10% reservation rates, but have opportunities to learn from their competitors to improve performance.

The online Car Rental category does not get discussed heavily, but is significantly important to the overall online travel industry. The volume of reservations being made represent a large part of travelers' budgets, and the softness observed taking place within the last few months illustrate that the category can be an indicator of the health of the travel category. For the Car Rental agencies themselves, the wide variances in performance from one site to the next represent the opportunities that exist in making improvements in their online channels.