Is Any Web Browser "Market Share" Data Reliable?

Whether you love or hate Microsoft, you have to admit that Firefox coming along late last year has been one of the best things to happen to Internet users in a long time. The fledgling browser's success has fueled new hopes that Microsoft will have some serious competition for Internet Explorer, which could motivate the company to consider some innovation for its browser. And so far this appears to be working quite well.

The frenzy surrounding Firefox is probably the single most important reason why we see a new-found spate of development on Internet Explorer version 7. It is reminiscent of the period when version 4 was being created; back then, IE 4 was Microsoft's weapon of choice to crush Netscape's Navigator.

The current estimate for Firefox market share is 10 percent, give or take a few percentage points. In some quarters, market shares of Firefox are rising; others suggest that Firefox's market share is on the decline again. And it isn't easy to get more details and understand how this market share is calculated.