Amazon made its debut pitch at the Upfronts annual ad sales event on May 14, competing with major media networks and highlighting its push beyond digital ads (Annie Palmer/CNBC)

Annie Palmer / CNBC:

Amazon made its debut pitch at the Upfronts annual ad sales event on May 14, competing with major media networks and highlighting its push beyond digital ads  —  Amazon has become a growing threat to digital ad incumbents Meta and Google, attracting billions of dollars a quarter from brands …