Amazon, Walmart, and others are in a war for talent as they build advertising arms. Amazon recently listed more than 2,800 advertising jobs on its site while Walmart's advertising arm, Walmart Connect, had nearly 1,000 openings. The biggest hirers were Walmart, Amazon, where advertising headcount has grown roughly fourfold in the past two years, and Instacart, per Revelio Labs' data. Walmart started building an ads business, Walmart Connect, in earnest in 2019 and has turned it into a $2 billion-plus revenue stream. Movement of advertising hires to Instacart, Walmart, Amazon, Jan. 2021-present.

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