There are few questions mobile payment followers like to debate with as much gusto as "What's Apple up to?" A new patent application unearthed by Apple Insider will only add to the discussion.

The patent, filed earlier this year, is called "Method and System for Managing Credits via a Mobile Device." It describes a system that combines a virtual currency in the form of tokens or coupons with a monetary value that could be stored in a cloud-based digital wallet and used for a number of services, including making purchases in-store or online as well as topping up mobile services.

The system described by the patent includes a method for users to receive the tokens by participating in advertising through from third parties, which seems to mean brands using the system to connect with and reward consumers viewing their marketing content.

It's not exactly clear from the patent application how Apple would implement the patented method into a workable product. It mentions all kinds of mobile payment technologies from direct carrier billing to peer-to-peer to NFC. And it should be stressed that this is just a patent application, meaning that it doesn't represent anything Apple is planning on launching.

Regardless of the specifics of the patent in the real world: the application shows that Apple has people within its organization who are continuing to focus on expanding mobile payments through its devices. The Passbook application, Apple's "mobile wallet lite," isn't the end of the company's mobile payment plans.

The importance of that Apple's efforts in mobile payments is obvious given its share of the smartphone market. So whether or not Apple opts to go with NFC or a cloud wallet or a bitcoins or whatever, Apple isn't done with mobile payments. And what happens when Apple comes out with a true mobile payment product, well, that's another question up for debate.

Read more about digital/mobile wallets.