cubeCar maker Nissan wanted to advertise its new Nissan Cube car, and so it created an iPhone game that lets users customize the car — just as they can in real life.

To do so, Nissan turned to Double Fusion, an advertising company that places ads within games.

The free game, called “cubeparty roundup,” lets you use the iPhone’s accelerometer, which detects which way you’re tilting the iPhone, to control the driving of the car through an urban 3-D landscape.

This is part of the trend in the game business that I call “iPhone migration.” Developers, publishers and now in-game ad firms have all heard the siren song of Apple’s new device, which along with the iPod Touch has sold more than 40 million units.

Jon Epstein, chief executive of Double Fusion, says the company is testing the waters with the Nissan deal. When Nissan approached Double Fusion about the project, Double Fusion coordinated with iPhone game developers that it knew — Coresoft in this case — and put together a packaged deal for Nissan, which doesn’t have its own game development talent.

“We’re like the broker and helped conceptualize the game in this case,” Epstein said. “It’s a case of responding to a customer’s request.”

Double Fusion usually inserts ads into games in opportune segments, such as on a billboard in the landscape of a game. But since the Cube car game is sponsored by Nissan, it doesn’t have any dynamic in-game advertising.

“My hope is that within a year we can move into the dynamic side of the business,” he said.

In the meantime, rivals such as AdMob and Greystripe have already moved into the business of inserting ads into iPhone games. The iPhone is a solid opportunity, since advertisers will pay more to reach the lucrative iPhone market. But Epstein says it isn’t as big as doing ads in console games or online web sites.

Double Fusion’s overall goal is to get ads to gamers wherever they are, regardless of platform. It will be interesting to see if the Nissan-branded game catches on, as the top iPhone games list has relatively few branded games.

The in-game advertising business has been hurt ever since the recession took root. In that sense, it has been hit like other parts of online advertising. But Epstein says the business hasn’t been trashed. He notes that there are 12 to 15 PlayStation 3 games coming this year with Double Fusion ads in them. Last year, it was just two or three. Still, some in-game ad companies have hit hard times. IGA Worldwide put itself up for sale earlier this year, and Microsoft laid off 28 percent of its Massive in-game advertising division.