[Update: Facebook has responded with clarifications about its Nov 4 policy change. Comment inserted below].

Appsflyer, a company that measures ad performance, has created a way for advertisers get real-time return on ad-spend data for Facebook campaigns.

The move is significant because it makes Appsflyer the first third-party measurement company to respond to Facebook’s decision to force measurement companies to drop personal device data from other personal data collected from ad campaigns.

Third-party measurement companies like Appsflyer, Kochava, Adjust and Apsalar have typically passed both device-level data and related meta data on to advertising companies. These advertisers then use the data to drive things like app-install campaigns more effectively. We reported on Facebook’s controversial decision last week to stop this beginning Nov 4, and cited an executive at one big game company that said he would no longer rely on third party measurement companies like Appsflyer.

But Appsflyer’s deeper integration with Facebook to show ROI for the first time — which will arguably make Appsflyer the best place to get data after Facebook’s aforementioned move — shows that the measurement companies are responding with more innovation, to stay relevant. This may discourage big advertisers from feeling the need to build such tools themselves.

VentureBeat learned of the Appsflyer move by discovering this link yesterday and we talked with several sources about what it means. The sources requested anonymity, in part out of fear from retribution from Facebook.

The deadline to comply to Facebook’s decision is on Nov 4, and so Appsflyer’s advanced integration with Facebook, which apparently showed up last week for advertisers, comes nicely before that deadline.

Appsflyer is releasing this even before Facebook has made any public comment about it. It’s unclear if that is what Facebook is intending for the future of measurement or not. Mike Manning, a Facebook spokesman, did not respond to a request comment. AppsFlyer declined to comment on this story.

To be sure, Appsflyer’s solution doesn’t roll back the full impact of Facebook’s Nov 4 change. Advertisers will still not be able to do what they’ve been able to do until now: export device-level information on users from Appsflyer, and keep it attached with all the other personal data, including post-install activity, about those users, so that advertisers can retarget them with offerings.

Instead, by hooking up with Facebook’s back-end, Appsflyer can let the advertiser do the best, equivalent by going through Facebook’s back-end to do it. Using Appsflyer, advertisers can retarget all users that match certain demographic data or that have taken certain actions.

The big difference, of course, is that sophisticated advertisers could before import everything into their own business intelligence platforms and do custom calculations on the data — giving many of them competitive advantages. These include companies like Supercell, Wooga, Kabam, King, Storm8, Machinezone and many more. They can’t do this anymore, and so are dependent on being routed through Facebook. And this means, of course, that they can’t build on their own profile database, because they can’t access the actual device-level ID information from Facebook.

Facebook makes up about 25 percent of the market by volume, according to estimations we’ve heard.

The latest Appsflyer feature combines in-app activity and lifetime value data with ad cost and other campaign details from Facebook. We’re hearing that it requires Appsflyer to access Facebook’s APIs to receive impression, click and cost data.

We’ve invited Appsflyer’s U.S general manager Assaf Vaknin to speak at our MobileBeat event in SF on Monday and Tuesday. He’ll be speaking on the “When and Where is your story working” panel at 11am Monday, and we hope he can share more information on all of this.

Until now, neither Facebook nor its third-party mobile measurement partners were able to tie user’s post-install behaviors to the amount of money spent to acquire them. Anyone wanting to calculate ROI on a device level was required to do a lot of manual work, pulling reports from multiple sources. The bigger game companies with lots of resources were able to do that, but most other advertisers couldn’t afford to do this. With the pulling by Facebook of device-level attribution data, even big companies can’t do this on their own anymore. This keeps Appsflyer relevant — at least for now.

[Facebook spokesman Mike Manning has responded with the following statement:

“Our Nov. 4 policy change will have no effect on developers’ ability to (a) export post-install data from their MMPs, or (b) use such data for retargeting purposes. It only limits developers’ ability to export attribution data that Facebook provides to MMPs — data which developers are prohibited from using for ad targeting or profile building today per our Ad Policies and terms.

There will be absolutely no change to the targeting practices advertisers are allowed to do with their post-install data after the November 4th policy change goes into effect. This includes exporting post-install data directly to their MMPs, running calculations, and then using the results to generate Custom Audiences on Facebook.”]

Appsflyer counts the The Wall Street Journal, L’Oréal, Baidu, Samsung, Mail.Ru and Hipmunk among its clients.

Below is an image of an “aggregated performance report” created within Appsflyer’s Facebook integration feature.

[Update: The shakeup in the industry continues. Ad measurement company Tune has just acquired Artisan Mobile, and Kochava is releasing messaging support]

[Update
aggregated performance report