Commonwealth Bank of Australia (ASX: CBA) shares are marching higher today.

Shares in the S&P/ASX 200 Index (ASX: XJO) bank stock closed yesterday trading for $143.85. At the time of writing, shares are changing hands for $145.07 apiece, up 0.85%.

That's the latest price action for you.

Now here's why the bank is stepping into the advertising business.

CommBank steps into the advertising business

In an announcement unlikely to have a material impact on CBA shares today but one that could help support the ASX 200 bank stock longer term, CommBank reported it will launch its owned media network. This will see Australia's biggest bank open its physical and digital channels to partners and advertisers for the first time.

The nascent media network, dubbed CommBank Connect, is a first for any Australian bank.

CBA said that as part of the move, it will enhance its digital merchandising screens in its branches and owned media ecosystem, providing its customers with "engaging content and enhanced communications channels".

The bank aims to expand its coverage to include more than 2,000 digital screens in metro and regional areas by 2025.

CommBank Connect is powered by CommBank IQ, a joint venture between CBA and data science company Quantium.

What did management say?

Commenting on the media network rollout that could provide longer-term support for CBA shares, chief marketing officer Jo Boundy said, "The launch of CommBank Connect is a significant step for CommBank, as we improve our customers' experience and deepen the connection between content and commerce."

She continued:

We know leading global brands are growing their owned media channels to deliver more dynamic, relevant, and valuable experiences. We're excited to be enhancing our digital and physical channels to better support our partners and advertisers in reaching our customers, who can then connect more effectively with the brands they love.

Boundy said CBA is well positioned for this move through its owned media channels and "by leveraging our scale and broad reaching customer communication infrastructure".

Nick Smith, managing director at Medium Rare Content Agency, added, "As the advertising sales and content partner for CommBank Connect, we're excited to use our experience in creating sustained, engaged audiences for Australia's most iconic brands."

CBA already has some big-name companies aboard as foundation launch partners. These include Qantas Airways Ltd (ASX: QAN) and Myer Holdings Ltd (ASX: MYR).

How have CBA shares been performing?

CBA shares have been on a tear over the past 12 months. Defying a raft of bearish analyst forecasts, the ASX 200 bank stock is up more than 44% since this time last year.