Firefox has made a lot of headway the past few years. It’s risen from relative obscurity to be the first real alternative to challenge the de facto standard, Internet Explorer, since Netscape.
The problem is that figures of how popular the program is could be based on anything from usage patterns to the number of downloads.
Usage is quite easy to gauge and would seem to be more accurate, but usage figures just don’t produce the kind of jaw-dropping numbers that make headlines. Why don't these two figures agree?
Because not everyone who downloads uses it, and not everyone who uses it continues to do so.
“Firefox's claims to success have been supported by clocking up the number of downloads, encouraged by payments from Google, but it turns out that 75% of the people making those downloads don't "continue to use it actively."
Mozilla also has a 12-point plan to increase retention levels, though it's actually an 11-point plan with one item repeated.
Well, I'm not convinced that 25% is such a bad figure. I remove at least 90% of the programs I download and try, often within seconds. Sturgeon's Law applies.”
The fact that Microsoft recently released an updated version of Internet Explorer (7) might contribute to users swapping back, especially as Vista comes pre-loaded with IE7.