Firefox data shows we're blocking ad trackers now, not just ads

Millions of us have discovered browser extensions like AdBlock Plus and uBlock Origin can declutter web pages. Now, judging by new data released by Mozilla , it seems we're also discovering we can block website software that tracks us on the internet, too.

With the November release of Firefox 57, the first Firefox Quantum version, Mozilla added an option to let people block all trackers. Since then, the fraction of people who enabled Firefox's tracking protection feature has grown, from none to 1.3 percent.

That's not a big fraction, but the rise has been steady -- and given that Firefox has about 250 million monthly active users, it represents the choice of about 3 million people. And in some areas, the percentage is higher: about 2 percent in the United States and 3 percent in France.

All in all, it adds up to a serious new rebuke of a key part of the financial system that makes the internet tick. Online ads have funded the explosive growth of free services like Google search, YouTube and Facebook, but just like ad blockers before them, ad tracking blockers threaten to make it harder to survive financially online. The combination of tracker disadvantages -- slower websites and privacy concerns highlighted by Facebook's Cambridge Analytica scandal -- indicate that websites won't be able to rely on trackers.

What's a tracker?

Trackers, which come along with websites or ads shown on them, are designed to identify individuals so advertisers can figure out our interests and show us potentially lucrative ads based on that data. Trackers are the reason why you might see an ad for a particular product after visiting a different website mentioning it.

You might not like how trackers let advertisers build profiles of you -- or how the software can slow down your browser and gobble up your network data.

That's why extensions like Privacy Badger and Ghostery are common, and why browsers are getting more assertive even without plugins. In addition to Firefox's tracking protection option, Apple's Safari has technology called intelligent tracking protection that blocks some trackers. And browser startup Brave, led by Mozilla co-founder and former Firefox leader Brendan Eich, blocks all trackers.

Mozilla also released data showing the widespread use of ad blockers.

Worldwide, 9.4 percent of Firefox users have installed AdBlock Plus, and 3.3 percent have installed uBlock Origin. That makes them the top two extensions people install to customize their web browser.

Usage is even higher in France, where 21.6 percent use Adblock Plus and 6 percent use uBlock Origin, Mozilla said. In Germany, it's 16 percent and 5.3 percent, respectively.

Mozilla's Public Data Report

Mozilla released the data as part of a new project to share details on what's going on with Firefox's millions of users. Mozilla gathers the data and starting Tuesday, with a project called the Firefox Public Data Report, shares aggregate statistics on things like default language and hardware power.

That can be useful to any developer trying to set priorities and answer software questions like which operating systems they should support, said Rebecca Weiss, head of Mozilla's public data science effort.

"We get to see humanity in a state that you don't often get a chance to," Weiss said.

For now, the data report covers only Firefox usage on personal computers. Mozilla hopes to add details from its Android and iOS browsers for smartphones and tablets , too, Weiss said.

Mozilla had already shared some hardware details like which graphics processors are most widely used among Firefox users, how much memory is installed, and how many processing cores their PCs have. Now it's adding usage details that show factors like the tracking protection statistics and activity details like the monthly user totals, too.

The telemetry data has been useful for Mozilla's Firefox decisions. Seeing the rising usage of Windows 10 over Windows 7 , Mozilla gave the Quantum a style that fit in better with the newer Microsoft operating system, said Nick Nguyen, vice president of Firefox.

Slumping Firefox usage

And it shows -- at least so far -- that the high-profile Quantum overhaul of Firefox hasn't yet turned around Mozilla's waning presence as it competes with Google's dominant Chrome. When Quantum launched, there were about 300 million monthly active users. Now that number is down to 256 million -- though to be fair right now Firefox is in the middle of a seasonal "summer slump" in usage.

"There are lots of plausible explanations," Nguyen said of the decline. "We don't know why."

But he hopes that sharing the number will ultimately help Mozilla pursue its mission to help build a web that's not seen just through the browsers of tech giants Apple , Google and Microsoft.

"People should see that number," Nguyen said. "I want Firefox to survive. If people do care about Firefox, they can see they're contributing to an independent internet just by using it."

First published Aug. 28, 6 a.m. PT
Update, 10:10 a.m.: Adjusts usage statistics with more-precise numbers.

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