Later in the article: "Some brands remain leery of the company, viewing it as a competitor. Even as it helps other brands market their own products, Amazon is increasingly hawking its own private labels as well."
"Ad agency executives said Amazon’s strength is its ability to tell advertisers if their ads have led to purchases on its site.Amazon’s Rise in Ad Searches Dents Google’s Dominance | WSJ
“The shift from Google to Amazon search is simple; Amazon has the audience, the transaction, and the loyalty to Amazon Prime, which clients can capitalize on,” said Shane Atchison, chief executive officer of North American operations at WPP’s Wunderman Thompson.
Amazon’s advertising ambitions have steadily grown. Beyond search, it offers other opportunities for marketers including display ads, TV-like ads in live sports telecasts and targeted ads it serves to people as they travel around the web. Overall, it is now the third-largest digital ad player behind Google and Facebook Inc.—the “duopoly” that combined controls about 60% of U.S. online spending."