update: I've posted a much clearer graph here.
I was watching the Google IO broadcast this morning and saw a cool slide showing Chrome user growth over the better part of the last year. They're rightly proud of going from 30 million users to 70 million users during that time. I grabbed a screenshot of the broadcast:
So, how does that compare to Firefox growth over the same period. Here's what it looks like when you plot Firefox user growth on top of that Chrome chart.
The blue line is Chrome and its numbers are on the left vertical axis. The orange line is Firefox and the numbers for it are on the right vertical axis. Firefox gained just over 100 million users in the same period that Chrome gained just over 40 million users.
(That dip you see in the Firefox line is nothing to worry about. Lots of regular people out there surf quite a bit less during the winter holidays. We see a similar, but far less substantial dip in the summer when lots of folks, especially in Europe, go on vacation.)