What is it? Microsoft’s new ad network helps retailers build and maintain their own media networks, boasting “ready-built demand, expansive ad supply, and access to high-intent shoppers.” Using Microsoft’s new product can help retailers reach profitability, according to the software company.

What is the opportunity? US retail media ad spend will reach $45.15 billion this year and cross the $100 billion mark in 2027, according to our forecast. Over 75% of those revenues will come from Amazon.

Why does this news matter? Microsoft already took aim at Amazon’s retail media dominance when it unveiled its Microsoft Retail Advertising Network back in January. That offering was aimed at helping retailers “understand their retail media business more effectively,” according to Kya Sainsbury-Carter, vice president of global partner and retail media at Microsoft, as reported by Modern Retail back in January.

But this new ad network appears to be more focused on helping retailers get their retail media networks off the ground in the first place. The retail media space is already getting more crowded, and with tools to help launch new networks, we can expect to see even more players.