• by Wendy Davis , Staff Writer @wendyndavis, July 25, 2013

Mozilla is planning to roll out a system that will enable publishers to personalize content to Firefox users based on their Web-surfing history.

Here's how the system will work: When Firefox users visit a publisher that is participating in the initiative, the browser will ask users whether they want to share information about the categories of content they tend to like -- such as sports, or gardening. Firefox can access data in people's browser histories -- at least when people don't clear the files -- and can then make assumptions about people's interests based on those sites. Firefox also will give users a dashboard that allows them to add or delete interest categories.

The company only intends to share that information if people opt in. “Our exploration into personalization is an attempt to help consumers get the most relevant content, at the right time, in a way that makes them feel comfortable by incorporating transparency and choice,” Mozilla Senior Vice President Harvey Anderson writes on the company's blog.

Product Manager Justin Scott illustrates the platform with this scenario: “Let’s say Firefox recognizes within the browser client, without any browsing history leaving my computer, that I’m interested in gadgets, comedy films, hockey and cooking. As I browse around the Web, I could choose when to share those interests with specific websites for a personalized experience. Those Web sites could then prioritize articles on the latest gadgets and make hockey scores more visible. Destinations like the Firefox Marketplace could recommend recipe and movie apps, even if it’s my first time visiting that site.”

For now the company is not rolling out a platform that would enable ad-serving based on the same type of browser data. At least not yet. Whether it will do so in the future remains unclear.

Still, some ad industry representatives are already fuming at Mozilla's announcement, given that Mozilla also plans to prevent ad networks from setting cookies. Mozilla's critics have said for months that blocking third-party cookies will undercut some forms of online advertising by preventing networks from making inferences about users' interests; without that ability, publishers won't be able to monetize sites by serving ads based on users' presumed interests.

At the same time, Mozilla's system isn't comparable to the current tracking technology, because Mozilla's initiative will be opt-in -- meaning that publishers will only see the interests that users decide to share. That's very different from the status quo, where ad networks (and other ad tech companies) take it upon themselves to categorize users and then share that information, unless consumers explicitly opt out.