kurtz_tan writes "News.com reports that the popularity of alternative Web browser Firefox continues to rise at the expense of Microsoft's Internet Explorer, according to a new study by WestSideStory. The study measured market share by embedding sensors on major web sites such as those of Walt Disney, Best Buy, Sony and Liz Claiborne. WebSideStory retrieves data from 30 million internet users a day passing through its monitored sites. The company then takes a snapshot of two days and compares the growth. Since beginning its measurements last summer, WebSideStory has been cautious to draw any broad conclusions about Firefox's popularity. This time around, the company said many people are not only downloading Firefox, they're sticking with it and using it."