Given the debate over F2P and in-app purchases, perhaps we forget how long the monetisation method has been in existence.

Indeed, in the case of Angry Birds, which found success as a paid game, by September 2010, it had introduced its first IAP the 99c Mighty Eagle smartbomb.

Showing how long ago it was, we spoke to then Rovio CEO Mikael Hed, following his announcement of the IAP at Nokia World 2010.

When you're the best selling mobile game in the world with seven million sales across all devices, and another 11 million downloads of your free versions, how do you make more money?

According to Mikael Hed, CEO of Rovio, the Finnish developer behind Angry Birds, the answer is add an in-app purchase that will enable gamers who are stuck on one level to overcome their frustration.

"We want Angry Birds to revive stress not increase it," Hed explained, at Nokia World 2010, as he introduced the Mighty Eagle in-app purchase.

Is it a bird?

This acts as a smart bomb to clear any level you're stuck on, but to ensure balanced gameplay, the Mighty Eagle can only be used once per game to clear any level.

If you want to use it again, you will have to clear that level using the normal arsenal of birds before the Mighty Eagle is again made available.

"When your bird arsenal isn't enough, and you're stuck on a level, you summon the Mighty Eagle," Hed said

Of course, by summon he meant buy as an in-app purchase, something demonstrated in this context via Nokia's Ovi Store.

The Mighty Eagle will also be made available on the Apple App Store via an update to iOS game, and we'd expect it to feature on the Android version of the game soon to be released.

Pricing wasn't announced but we'd expect 99c.

"From a business perspective, this is the end of mobile games as a commodity and the start of games as a service," Hed explained.