Freemium first: In-app purchases to push app spending to $75 billion by 2017

The latest app revenue projections published by Juniper Research suggest consumers will spend more than $75 billion a year on apps by 2017.

That's a figure the firm claims will be largely driven by increased take up of in-app purchases, as well as the continued roll out and implementation of other new monetisation models.

The company also claims what it bills as intensifying competition between app marketplaces will encourage new innovations, such as better search and discovery tools, thus "encouraging developers to write their apps for the more peripheral stores."

The report goes on to project that the amount of revenue amassed by apps at the point of download will fall drastically, only making up a quarter of the $75 billion that apps will supposedly be raking in.

Juniper notes that such a shift in buying behaviour will present a "challenge for developers who are seeking to maximise the number of users and revenues from their app."

In short, Juniper predicts that the hold freemium apps have over consumers is only set to intensify.

"It is not only developers who are seeking to capitalise on their user base," says report author Sian Rowlands.

"Many app stores are also implementing carrier billing to ensure that unbanked consumers are able to pay for apps, which will contribute to the strong growth in app downloads."

You can sample Juniper's findings in full by buying its Future App Stores report, available for £2,500 (around $3,800).