For Dangling Concepts, the US-based developer of Air Soccer Fever, using Nokia Ad Exchange (NAX) to increase the mobile game’s discoverability is a winning move. This past December and January, when Air Soccer Fever was featured in a NAX ad campaign, daily downloads of the game to Windows Phone devices more than doubled, from 1,500 a day to 3,200.

Air Soccer Fever is a casual swipe soccer game available for both Windows Phone 7 and Windows Phone 8 smartphones, and Windows 8 tablets. Available in both free and $0.99 (USD) Pro versions, the game can be played by either one or two persons in the same room or by multiple online and Wi-Fi players in real time.

NAX is a private mobile advertising exchange offered by Nokia that offers app developers and publishers access to more than 120 ad agencies and networks worldwide. NAX also lets publishers incorporate in-app advertising and gives them a dashboard to track their apps’ performance. NAX can be used for both free house campaigns aimed at cross-promoting apps and paid campaigns in which developers bid for ad space on the apps of others.

‘Integrating NAX ads was very straightforward’, says Imran Shafiq, president of Dangling Concepts. ‘We had no issues or bugs, so we spent no time in troubleshooting.’

Because Air Soccer Fever is truly a global game – it lets players choose teams from 100 nations around the world—Shafiq uses the NAX dashboard to target specific countries based on their ad prices. ‘The NAX dashboard is one of the best we have seen’, he says. ‘The UI is clean, and it has great features.’

One feature Shafiq finds especially useful within the analytics dashboard is ‘Performance by Country’ option. This shows a breakdown of ads served by country, along with their comparative costs (expressed as cost per thousand, or CPM). ‘That way’, Shafiq explains, ‘we can fine-tune our ad targeting’. The result: In last 2 months, NAX provided 40% of total ad traffic and revenue for Dangling Concepts. This month Shafiq and his team have redirected more traffic to NAX due to great eCPMs as compared to other ad networks. According to Shafiq, NAX will provide 70% of the overall ad revenue moving forward.

Although Air Soccer Fever has not yet been promoted with either paid ad campaigns or house ads, Dangling Concepts plans to try both soon. For example, when the developer releases his next new game, the game will display house ads for Air Soccer Fever to cross-promote and drive downloads. These cross-promotional opportunities could be impressive: every day, an average of 15,000 unique users play Air Soccer Fever, according to Flurry Analytics figures cited by Shafiq.

Dangling Concepts also finds that when it comes to in-app ads, a little restraint can be beneficial. The free version of Air Soccer Fever shows ads only when the game is paused, never during game action. Similarly, the game’s menu pages only show ads at the bottom of the page, so the ads do not cover or overlap the menu UI. This restrained approach seems to work: Shafiq reports ‘great’ click-through rates on Air Soccer Fever ads, in some regions reaching as high as 15 per cent.

Check out Air Soccer Fever on the Windows Phone Marketplace

Watch a video of Air Soccer Fever in action