Back in May, ABI Research claimed app downloads would rise to an annual figure off 44 billion by 2016, owing largely to a growth in the smartphone and tablet markets.

Rival IDC shares the view that the only way is up, but suggests its competitor may have overlooked one, crucial factor: in-app purchases (IAPs).

Delivered via its latest report – subtitled 'The Emergence of Postdownload Business Models' – IDC forsees app downloads coming in at more than four times ABI Research's prediction, one whole year earlier.

Free for all

The firm states that, rising from a base of 38.2 billion downloads in 2011, nearly 182.7 billion app downloads will be made globally by 2015 as "developers create apps for virtually every aspect of a mobile user's personal and business lives".

More important, however, is the suggestion that an increasing number of these apps with be sold without charge, with developers choosing to use IAPs or advertising to monetise their titles.

Quite simply, the more free apps on offer, the more consumers will download.

The art of 'appification'

"App developers are not only focusing on ways to "appify" just about every interaction you can think of in your physical and digital worlds, they are now focusing on longer-term sustainability issues," said VP of mobile and connect consumer platforms at IDC, Scott Ellison.

"The user sustainability trifecta of social networking, location, and the cloud are now increasingly being supported by the business model financial trifecta of application store purchases, in-app purchasing, and in-app advertising."

In short, instead of trying to justify a flat purchase price, developers are increasingly employing sophisticated ways of keeping players engaged for longer in their free releases, allowing apps to deliver a steady stream of revenue rather than one set burst at the point of purchase.

[source: IDC]