Nintendo is open to the idea of using a free-to-play business model for new franchises, company president Satoru Iwata has revealed.

But Nintendo's leader pledged that he won't add free-to-play or micro-transaction elements to existing series such as Mario or Pokémon, during an interview with Japanese newspaper Nikkei (translated by NeoGAF).

"We [as an industry] can now do distribution by digital means as well as micro-transactions, and the ways to obtain money through supporting entertainment have increased.

"I have no intention of denying charged games or the free-to-play model. If we were to talk about if Nintendo were to do that, however, I do not [have] much inclination to do that with Nintendo's established well-known products, where people trust their interesting-ness."

"...it is not a betrayal but the birth of an interesting idea through our new found freedom, that's all." Satoru Iwata

Iwata gave the example of New Super Mario Bros. 2, which was sold as a complete game. Post-launch, a number of extra Coin Rush courses were created and sold as paid DLC.

"We will not have a proverbial door to full enjoyment that can only be unlocked via payment. However, this is separate from, say, having something where because there are people who want more stages to play in Mario games, we will create new courses for those people and charge for them."

This all changes for new game franchises, though. Iwata said that for fresh ideas he is open to the idea of other methods of payment.

"For new titles with no established base, if, in the process of development, we found it to suit the free-to-play model, we might follow that route, or we might do something like 'cheap-to-play'," he explained.

"Our sales methods have been freed up and I have no desire to extinguish that freedom. If we were to release something like that, it is not a betrayal but the birth of an interesting idea through our new found freedom, that's all. I am not talking about changing how we sell Mario or Pokémon."

Iwata recently told Reuters that Wii U stock was selling "steadily", although launch sales were not as strong as the original Wii.