Much focus is being paid on the competing ad networks on iOS and Android at the moment, but mobile ad firm inneractive believes Nokia's Ovi Store is also a fruitful market.

As such, while inneractive's ad revenue acceleration system operates on six formats – including both aforementioned platforms – its the Ovi Store that is proving most fruitful.

The firm claims one out of every four app downloads on the marketplace now come equipped with its in-app ad platform, with seven of the top 10 also making use of the SDK.

Free app fiesta

It's a situation inneractive believes validates the free app model, with co-founder and CMO Offer Yehudai claiming studios can now make serious money from their titles without having to charge directly.

"Developers have realised that they can earn higher recurring revenue through placing advertising in free apps, than they could through app sales," said Yehudai.

"Publishers can make up to $20k per app a month - a 200 percent increase since February - by using inneractive's ad acceleration platform."

Mixing things up

The key to inneractive's swift success so far – at least in the company's view – is its ability to tap up 45 separate ad networks across the platform.

As a result, apps signed up see eCPM four times the industry average, with ads having a 90 percent fill rates and 3 percent average click through rates (CTR), based on the firm's figures.

"Advertising is a dynamic marketplace, with CPMs constantly changing," added Yehudai.

"It's much too time consuming for an app developer to continually compare ad networks for the best pricing by himself. Inneractive's sole focus it to maximise developer revenue."

You can find out more from its website.