App Store Downloads Could Surpass 25 Billion in Five YearsIt’s the era of the app.

But that much we already know.

What’s a little more cumbersome to figure out is how consumer appetite for apps can translate into dollars for the app makers and marketers who dabble within. Those, however, who do figure out how to best monetize their mobile territory in the app world stand to gain immeasurably.

A new Juniper Research report indicates that the annual number of consumer-oriented handset downloads is predicted to rise from less than 2.6 billion in 2009 to more than 25 billion in 2015.

The estimate, which others say may actually be “conservative,” is the product of anticipating the continuing emergence of network operators and vendors who now deploy their own dedicated apps and app stores.

The Juniper report suggests that the biggest players across the mobile value chain are “seeking to emulate Apple’s success with the App Store by launching own-brand storefronts.” While Apple’s App Store continues to claim the lion-share of attention in the app world, competition is rising, as observed, for example, by the growth of GetJar, which just recently passed the key 1 billion download threshold.

“Apple has been able to achieve several billion downloads from a comparatively small handset base because customers are buying the iPhone for the apps. That’s not been the case with other handsets,” said the report’s author Dr. Windsor Holden. “So even if you have a subscriber base of tens of millions, your addressable market is a fraction of that–and spread across a variety of operating systems and handsets.”

Juniper also observed that “freemium applications” are rapidly emerging as “the prevalent business model.”

“A growing percentage of publishers and developers are now offering applications free at point of sale, relying on monetization via in-app billing of subscription-based services, upgrades to premium content or micropayments for virtual items.”