Firefox users click through to Web site ads four to five times less often than do users of Microsoft's Internet Explorer, a German Web-advertising firm said Friday.
Based on its analysis of 1,000 sites and the click-through behavior of users equipped with various browsers, Frankfurt-based Adtech AG reported that only 0.11 percent of Firefox users click on ads. Internet Explorer users, on the other hand, click through at rates ranging from 0.44 percent (IE 6) to 0.53 percent (IE 5.5).
"The causes probably lie in the different surfing behavior [of Firefox and IE users], or switching on the popup blocker," said Dirk Freytag, AdTech's chief operating officer, in a statement.
Mozilla's Firefox sports an integrated pop-up ad blocker, but IE--with the exception of the updated edition in Windows XP SP2--does not.
Adtech also reported that Firefox's share of the browser business has grown significantly in the last several months in Europe, data that mirrors global trends recently noted by metrics vendors such as WebSideStory and OneStat.com.
According to Adtech, Firefox accounted for 5.5 percent of all browsers used as of the end of November, more than double the 2.2 percent of August.
The three monitored versions of IE--5.x, 5.5, and 6.x--now account for under 90 percent of all browsers used in Europe, said Adtech.