Amazon, With Little Fanfare, Emerges as Advertising Giant

Some marketers eager for a new digital ad alternative are also conflicted about the rise of Amazon--a competing retailer with its own in-house brands to sell--setting up a new potential source of tension. Amazon's ad revenue is on pace to double this year, to $5.83 billion, according to eMarketer. Its ad sales are expected to jump $28.4 billion over the next five years, according to Cowen & Co.--more than the combined increases in ad revenue for all television networks globally, according to figures from media-buyer GroupM. The cumulative effect is an earthquake whose tremors will be felt by anyone selling ads, including digital publishers and TV networks. Retailers like Walmart Inc., Target Corp. and Kroger Co., which get paid by brands to place products in desirable locations within their stores, are already losing business to Amazon, ad executives say.