Much of the power and popularity of Firefox and, to a lesser extent, Thunderbird, come from their addons. This shows just how powerful and popular:
Earlier this week, [addons.mozilla.org] served its 600 millionth add-on download. That’s original downloads, not including updates. We currently have over 4000 add-ons hosted on the site and between 800,000 and 1 million downloads every day. The site has around 4.5 million pageviews per day, not including services hosted on AMO such as update checks and blocklisting.
AMO now receives around 100 million add-on update pings every day, which means that of those 600 million downloads, about 100 million add-ons are still installed.
Amazing Mozilla. (Via Mozilla Links.)