
It’s no secret that Amazon's (NASDAQ:AMZN) ad business has been successful, driving $31 billion in 2021. Between their on-site sponsored products, header bidding solution (TAM), and off-site retargeting network, Amazon has pioneered ad tech innovation in the past five years.
But Amazon isn’t the only retailer recognizing the potential of retail media: brands like Walmart and Instacart have taken notice and built billion-dollar ad platforms to compliment their core business.