Marketers can (and do) glean valuable information about the types of products smartphone users are most likely to buy based on their day-to-day digital activities.

Age, gender and physical location can all influence the types of ads displayed on your phone, but the websites you've visited in the past — particularly e-commerce sites — are thought to play an even bigger role in many cases.

The problem is that some of us peruse products we don't actually intend to buy, for inspiration or perhaps aspiration, and serving an ad for $900 shoes to someone with a $90 budget does nothing for parties on either side of the equation.

A freshly granted U.S. patent suggests that Apple is working on a way to fix this — by checking a user's credit card balance before determining which ads they'll see.

Apple Patent credit card mobile ads

An illustration of Apple's 'method and system for targeted advertising of goods and services to users of mobile terminals,' as seen in a recently approved U.S. patent. (U.S. Patent and Trademark Office)

Essentially, those who opt-in to Apple's conceptual system would only be shown mobile advertisements for products they could afford based on their banking information.

"Goods and services are marketed to particular target groups of users sharing a common profile which may be selected to increase the likelihood of the users responding to the advertisements," reads the patent document, noting that user profiles "may be based on the amount of pre-paid credit available to each user."

"An advantage of such targeted advertising is that only advertisements for goods and services which particular users can afford, are delivered to these users."

Apple's application to patent this type of service, filed in March 2015, was approved by the U.S. Patent and Trademark office Thursday.

It is not known whether the company actually has plans to implement the ad-tailoring described in its patent, or if Canadians will ever have access to it.

As Business Insider notes, Apple's developers "come up with all sorts of ideas that the company patents but never actually produces."

The system proposed by Apple does differ in some critical ways from advertising programs that have previously come under fire in Canada for using personal data to target consumers.

For starters, Apple's program appears to be opt-in as opposed to opt-out.

Tim Cook

Apple CEO Tim Cook lashed out at tech companies that collect and sell user data 'for God-knows-what advertising purpose' during a speech in June, telling audience members that Apple 'doesn’t want your data.' (Stephen Lam/Getty Images)

This means that users would need to give Apple explicit permission to access their banking information, and to allow the company to serve ads based on the data it collects.

Several tech analysts have also posited that any financial data Apple uses would be "hashed," encrypted and stored on a user's phone, as opposed to in a central database, like Apple Pay.

"Hashed data tells advertisers that you are only one of thousands of anonymous people who are in a certain age bracket, with certain interests, and a certain history." wrote Jim Edwards for Business Insider. "Your specific personal data is never actually seen."

Others are a bit perplexed by the news of this patent's existence, given Apple CEO Tim Cook's relatively recent comments criticizing companies that collect and make money from users' data.

"Some of the most prominent and successful companies [in Silicon Valley] have built their businesses by lulling their customers into complacency about their personal information," Cook said to a Washington audience in early June. "They're gobbling up everything they can learn about you and trying to monetize it. We think that's wrong. And it's not the kind of company that Apple wants to be."