• by Mark Walsh  @markfwal, September 19, 2013

In its latest effort to link advertising on Facebook with offline sales, the social networking giant has introduced a new service that analyzes users’ mobile phones and wireless providers. It determines which ones switched devices or carriers after viewing an ad.

Facebook said the new Telco Outcome Measurement tool has shown telecom ads displayed in the desktop news feed are seven times more effective than right-side placements, while those in mobile are nine times more effective than ads on the desktop.

The new service, which Facebook said keeps users’ personal information shielded from marketers, is rolling out today to telecom industry advertisers widely in nine countries, including the U.S., with a goal of 25 by year’s end.

With a mobile user base that swelled to 819 million globally in the second quarter, it’s easy to see the attraction of the service for wireless providers and handset makers. Within that population, Facebook created test and control groups to see how and when an ad leads to actions like switching to new phones or carriers.

The social network’s apps automatically detect a user’s phone type and carrier to optimize service accordingly.

“We can provide our partners with insights regarding ROI, differences in adoption rates of devices or carriers segmented by demographic groups, and the types of ads and frequency of placements that yield the best ROI for carriers and operators,” stated a Facebook blog post today.

Three of the four major U.S. wireless operations, including AT&T Mobility, are already using the measurement tool.

Telecom is the third-highest spending category in U.S. digital advertising after CPG and retail, according to eMarketer. And research firm IDC projects telecom spending will reach $5.6 billion this year and $6.3 billion next year. Facebook declined to say what share of its own sales come from the category.

Since going public last year, Facebook has taken greater steps to convince marketers that advertising on the social network pays off in real world sales. A year ago, it partnered with third-party data firm Datalogix to measure the impact of offline sales for CPG and retail companies.

“We continue to look at how we can develop similar solutions for other categories,” said a Facebook spokesperson on Thursday.