Today we’re launching cross-device reporting for Facebook ads, enabling advertisers to see for the first time how people are moving between devices — across mobile apps and the web — before they convert.

Imagine seeing an ad for a product on your mobile phone while in line at the bank. Do you immediately make a purchase on your phone? Probably not. But perhaps you go back to your office later that day and buy on your desktop computer. Such cross-device conversions are becoming increasingly common as people move between their phones, tablets and desktop computers to interact with businesses.

Facebook already offers targeting, delivery and conversion measurement across devices. With the new cross-device report, advertisers are now able to view the devices on which people see ads and the devices on which conversions subsequently occur. For instance, a marketer can view the number of customers that clicked an ad on an iPhone but then later converted on desktop, or the number of people that saw an ad on desktop but then converted on an Android tablet.

In early tests, marketers have used Facebook cross device reports to better understand the role of mobile in their campaigns and explain the differences in reports by third-party analytics tools that do not account for cross device conversions.

“This report has provided unprecedented insights into the cross-device shopping behavior of our customers,” says Nisho Cherison, director of online marketing for One Kings Lane.

Josh McFarland, CEO of TellApart, a Facebook Preferred Marketing Developer, adds: “Tracking click and conversion data deterministically across devices has confirmed what we know to be true: mobile ads drive commerce everywhere. This new reporting from Facebook has been a game-changer in our ability to help clients like Neiman Marcus and Sur La Table correctly value and invest in their mobile ads efforts.”

To view cross-device conversions for campaigns, go to your Facebook Ad Reports, click Edit Columns, and select Cross-Device on the left-hand menu.