Uncovering and explaining how our digital world is changing — and changing us.

At Google’s developer conference this week, the search giant announced it will be rolling out a spate of new privacy measures, including simpler controls to block tracking cookies on its Chrome web browser. The moves have been much more well-received than Facebook’s avowed privacy pivot that was reiterated at its developers conference last week.

But Google’s privacy measures will only be effective if people opt to use them.

Cookies are tiny files websites place on your computer that allow companies to keep you logged in or see which websites you visit. They also allow advertisers to track you from site to site, sending you ads for shoes on, say, a news site, if you earlier happened to be searching for shoes on Zappos.

Google’s move will allow users to more easily restrict cookie tracking while preserving their logins and preferences. Blocking third-party cookies — cookies from domains you haven’t directly visited, which are often used to target ads — is an option Chrome users already had, though the option will now become more prominent.

But research has shown that the vast majority of people don’t update their browser settings. Most people don’t change the settings on any of their devices, meaning that what a manufacturer or product maker decides to include is what most people will experience.

Google itself knows the value of default options. It pays Apple billions of dollars each year to be the default search engine on Apple’s Safari browser.

“By not changing the default, by making it optional, Google is relying on people not changing it,” Brendan Eich, co-founder and CEO of Brave, a privacy-oriented web browser and thus a Chrome competitor, told Recode. “Chrome users may never know this is an option.”

Eich estimates that people opting out would be in the “single digits.” Google declined to speculate or disclose the percentage of current Chrome users that change their browser settings on the world’s most popular web browser. Chrome has a more than 60 percent global market share.

Google’s cookie news comes as regulators are sounding off on privacy, which has become a more important issue to rank-and-file Americans, as calls to break up big tech companies like Google proliferate. Privacy is also becoming something people want to buy. Google’s privacy announcements are an attempt to separate it from other tech giants like Facebook, which has been beleaguered by its many privacy mishaps, and even Apple, which is known for its security but also its price tag. In the privacy department, however, Chrome is still leagues behind Apple’s Safari browser, which has blocked third-party cookies by default for years.

Perhaps more important are Google’s other privacy announcements, like making it harder for companies to use fingerprints, which are a cookie workaround that uses your browser information to figure out where else you’ve been. Google is also now requiring that developers state whether cookies can work across sites, which could be used for more stringent control down the road.

Overall, Google’s changes are meaningful, but probably not as much as they are marketing.

“It’s a minimal net gain to privacy,” said Wes MacLaggan, SVP of marketing at Marin Software, an online advertising company that uses first-party cookies. “It’s a net gain nevertheless.”

As for cookies, it’s worth noting, however, that they aren’t that effective in the first place.

Using cookies to track people across sites is a complicated and imperfect procedure, according to Michael Tiffany, co-founder and president of cybersecurity company White Ops.

“It’s partly to blame for bad user experience, for getting retargeted for a product you already bought,” Tiffany told Recode.

Advertisers have already been moving to other tracking mechanisms, especially as people have shifted their internet usage to mobile, which doesn’t really use cookies. Smaller ad firms are instead working together to create a unified ID solution, which Tiffany says could be a more accurate and efficient way of targeting ads than the current cookie model.

And Google, the world leader in online advertising, doesn’t need cookies to track you around the web, as Julia Angwin reported in ProPublica. It can follow you across its services and devices as well as outside sites and apps that use Google tools, like AdSense, Analytics, or even YouTube.

“If they ban cookies but keep Chrome tracking, Google will be sitting pretty,” Eich said.

Still, cookies are important — if not as important as they used to be — to web companies and advertisers.

Presumably, any mass disavowal of cookies would also spell trouble for Google’s ad business and its partners — though, as mentioned earlier, Google has a lot of other data at its disposal.

“We think privacy is for everyone — not just for the few,” Google CEO Sundar Pichai said at the conference.

But when Google rolls out its cookie-blocking option later this year, privacy will be for those few who choose to enable it.

Recode and Vox have joined forces to uncover and explain how our digital world is changing — and changing us. Subscribe to Recode podcasts to hear Kara Swisher and Peter Kafka lead the tough conversations the technology industry needs today.