Facebook knows more about your life than Google, and now the network is putting that information to good use--at least for advertisers who want to sell you stuff.

The company launched a new ad platform called Atlas ahead of Advertising Week, which kicked off Monday in New York. Facebook has long used your demographic info and likes to show relevant ads to you in the News Feed, but Atlas takes those ads to the next level: around the Internet.

How it works: When you visit a site on your laptop or desktop computer, cookies track the pages you look at. That's why you'll see an ad on Facebook for Modcloth after browsing for new duds on the clothing site. But cookies don't work on mobile, so advertisers struggle to figure out what you're looking at. Because Facebook tracks your browsing activity if you're logged in to the network but not actually using it, Atlas advertisers can show you ads on third-party sites and apps. Your Facebook login is now officially more useful to companies than cookies.

Atlas gives brands and the media companies who work with them information about Facebook users, so an advertiser looking to target 24-year-old smartphone owners in New York can do so with just a few clicks. Facebook's first major Atlas partner is Omnicom, which counts Pepsi and Intel as a couple of its clients. Instagram is also on board with Atlas, so advertisers can track campaign performance on the photo-sharing app. Instagram's ad efforts are still in their early days.

Managing your privacy preferences

Are you thoroughly creeped out by the knowledge that Facebook can use both your personal information and your browsing activity to serve you ads all over the Internet? That's understandable. There are a few things you can do to protect your privacy. First, you can see exactly why Facebook is showing you specific ads by finding an ad in your News Feed and clicking the dropdown arrow. Then select: "Why am I seeing this?" You can manage your ad preferences from there.

Facebook has a wealth of data on you, based on where you live, what kind of device you use to access Facebook, pages you've liked, relationship status, etc. You can remove all of this information. Changing your ad preferences doesn't mean Facebook won't show you ads anymore, it just removes the personal information Facebook uses to determine which ads you'll see. FYI: The network repopulates your ad preferences from time to time with new information it gleans about you, so you'll have to manage this section often.

Facebook doesn't participate in do-not-track, but you can opt out of being tracked on the Digital Advertising Alliance's opt-out page. iOS and Android also have settings that let you manage your web-tracking preferences.

The social network isn't the only company to monitor your activity to target ads to you. Its direct competitor is Google, which reads your Gmails to serve you relevant display ads. If you use the Internet today, you're giving up a measure of privacy for the use of free services.