As Advertising Week kicks off in New York City, Facebook is announcing a new version of its Atlas ad platform, which it says represents the next step in tracking ad effectiveness across devices.

The company first acquired Atlas from Microsoft last year, but in recent weeks both The Information and The Wall Street Journal reported that an ambitious relaunch was in the works, with the aim of helping Facebook challenge Google.

In a company blog post, Facebook says that Atlas not only offers a new user interface, but has actually been completely rewritten.

(Update: Boring inside baseball, but this story had to be published ahead of schedule due to a broken embargo, and I guess that means Facebook’s blog post isn’t live yet. The link above is where the post should be found whenever it goes up.)

Perhaps most importantly, the company says it has improved the platform’s cross-device capabilities. The post points out the limitations in relying on cookies to track users and determine whether an ad is effective: “Cookies don’t work on mobile, are becoming less accurate in demographic targeting and can’t easily or accurately measure the customer purchase funnel across browsers and devices or into the offline world.”

Facebook describes its approach as “people-based marketing,” where advertisers can follow users across devices. Presumably that means Atlas can tell advertisers if someone saw their ad on, say, their smartphone and then made a purchase from their laptop, or vice versa. The blog post doesn’t go into much detail about how Facebook is doing this, but the Journal reported that the platform will be “linking users’ ad interactions to their Facebook accounts,” not just on Facebook itself, but on other websites and apps.

The company also says that it will be able to connect online ad impressions with offline sales — an area where Facebook has previously been working and developing partnerships.

And Facebook says it will be working with “a key group of partners that cross search, social, creative management and publishers.” Those partners include Instagram — which is, yes, owned by Facebook, but the post says that as a publisher, Instagram will be using Atlas “to both measure and verify ad impressions,” with presumably other, non-Facebook-owned publishers to follow.

In terms of getting advertisers on board, Facebook says it’s already partnered with ad holding company Omnicom — the first Omnicom clients to move to the new platform are Pepsi and Intel.