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When app creators want to promote their app, they mostly turn to Facebook.

The social network owns the most prime attention real estate, the News Feed, and it charges accordingly. This has worked out handsomely for Facebook.

Google wants in on more of the action. Its strategy is to pool many of the search giant's ad channels into one real estate listing — and then slash the price.

The executive leading this effort is Sissie Hsiao. It's a critical job: Google must milk more mobile ad money to keep growth in its core business steady.

Hsiao's primary weapon is a tool called universal app campaigns, which lets app developers promote apps across a bunch of Google properties — search, the Play app store, mobile YouTube videos — if they fork over money and let Google automate the spending.

After slowly unfurling the tool last fall, Google is going strong, placing it at the center of its strategy to claim the ad type that shows no signs of relenting.

"It’s a simpler way to buy and it harnesses all the power across different channels very easily for app developers," Hsiao told Recode. "That’s where we’re going to be investing a lot of our product efforts, now and in the next several quarters."

Apps are a brutal business. Google's pitch to small developers is that Google can alleviate the pain by helping them find users who will install and stay with their apps — and Google will drive down the costs.

Hsiao claimed RunKeeper, a fitness tracking app, was able to add 85,000 users in one quarter and cut its cost-per-install under 25 cents. (Average CPI rates are around $1.80 for iPhones and $1.20 for Androids, according to marketing firm Kenshoo; I've heard spending on Facebook can hit nearly $5 a pop.)

And Hsiao claimed that search ads in the Play app store, introduced last year, are going "incredibly well." Fattal Hotels, an Israeli company, used the format to grow its app revenue fifteen-fold, per Hsiao.

But, characteristically, the Googler didn't share much more internal data. She has, though, opened up more to partners.

"She’s very operational and in tune with her team," said Peter Hamilton, CEO of Tune, a mobile marketing firm. "She’s also reaching out in the industry to find out what’s happening outside of Google. It’s not always typical of Google."

That openness may be necessary given Google's position.

The company rules mobile advertising — it is set to take in $13.3 billion this year, nearly $5 billion more than second-place Facebook, according to eMarketer. Strip search ads out, however, and the companies switch spots; Facebook is expected to bring in $8.44 billion in display ads, nearly four times more than Google. (Facebook actually brought in about $4.26 billion in mobile ads in the first quarter alone.)

Hsaio, a 10-year Google veteran, took over all mobile display ads last summer. She's since added mobile search and Play ads to her portfolio — an indication that Google is trying to better organize its assault against Facebook.

One method for Hsiao's team is to convince app developers to promote their app on the web. During the year, the company has dribbled out a series of products to this end — ways to link to and stream apps directly inside mobile search. Expect to hear more about it at Google's I/O developer conference this week, along with new features for its mobile app ad toolkit.

Another area to look out for: How Google will manage this fight against Facebook on Apple devices. Apple has retrenched from some of its mobile ad efforts, but some of Hsiao's weapons still either won't work on iPhones (Play store ads) or may have difficulty getting traction there (app streaming).

One of the only public figure Google has shared on its app ads business is that it drove a 200 percent annual increase in installs, as of January. But that's just for Android phones, where Google exerts far more control.

"We’re stronger on Android; that shouldn’t be a surprise," Hsiao said. "That said, absolutely being a cross-platform provider is a top priority focus. And our iOS offering — we are actively working on it."