Previously we wrote about “the funnel“, and our desire to better understand how a download becomes an active and long-term Fx user. There, we suggested a way to measure this with some degree of accuracy, and since launching the project, we are now at the point of digging through the data seeking findings. Before presenting those findings, this post is meant to highlight how we launched funnelcake (the project’s name), and how we did so without comprising users’ privacy.

One goal within our process was to tie a Firefox download to a particular date, with greater accuracy. For example, we can tell that a Firefox download of 2.0.0.6 happened sometime between July 30, 2007 (2.0.0.6 release date) and September 18, 2007 (2.0.0.7 release date). With funnelcake, we were able to tie a build to a particular date.

On October 4th from 00:00:00 – 23:59:59 PST, we included an extension with Firefox 2.0.0.7 (en-US and de) that changed three preferences relating to the funnel. These preferences where:

• firstrun “Welcome to Firefox” URL
  • the default: http://en-us.www.mozilla.com/en-US/firefox/2.0.0.7/firstrun/
  • funnelcake: http://en-us.www.mozilla.com/en-US/firefox/2.0.0.7/firstrun/?f=1
• whatsnew “You’ve been updated” URL
  • the default: http://en-us.www.mozilla.com/en-US/firefox/2.0.0.7/whatsnew/
  • funnelcake: http://en-us.www.mozilla.com/en-US/firefox/2.0.0.7/whatsnew/?f=1
• update channel
  • the default: release
  • funnelcake: release-cck-mozilla01

If the build is opened, and we see hits on the differentiated URLs, we know that the build was downloaded on October 4th, 2007. This is like knowing that 2.0.0.6 builds were released between July 30th and September 18th, except for a specific date. This allows us to gain insight into when the build was released and when it is subsequently used.

The extension is listed under the addons manager as, “Mozilla Settings for October 2007”, with the description, “October 2007 settings for the automatic update feature of Firefox. This extension points Firefox to an alternate update channel corresponding to October 2007, and can be disabled or removed safely without affecting automatic updates.”

We’re still wading through the findings — and should have some results to post. Since we are not collecting anything user identifiable, we feel we’ve navigated through the necessary precautions allowing us to safely share what we find!