For the first time on record,the number of advertising-specific jobs in the U.S.is declining in the middle of an economic expansion,according to government data.What"s going on?It"s certainly not a case of fewer advertisements.The typical American has gone from seeing about 500 ads each day in the 1970s to about 5,000 today,according to a common industry statistic.That is one corporate message for roughly every 10 seconds of waking life.Instead,the mysterious decline can be explained by two developments.First,there are Facebook and Google.They are the largest advertising companies in the world-and,quite likely,the largest in the history of the world.Last year,90 percent of the growth of the digital-advertising business went to just these two firms.Facebook and Google are so profitable because they use their enormous scale and data to deliver targeted advertising at a low cost.This has forced the world"s large advertising firms to preserve their profitability through a series of mergers,accompanied by jobs cut.s in the name of efficiency.The emergence of an advertising duopoly has coincided with the rise of"programmatic advertising,"a term that essentially means"companies using algorithms to buy and place ads in those little boxes all over the internet."As any Macl Men fan might intuit,advertising has long been a relationship-driven business,in which multimillion-dollar contracts are hammered out over one-on-one meetings,countless lunches,and even more-countless drinks.With programmatic technology,however,companies can buy access to specific audiences across several publishing platforms at once,bypassing the work of building relationships with each one.That process produces more ads and requires fewer people-or,at least,fewer traditional advertising jobs and more technical jobs.Second,there is the merging of the advertising and entertainment businesses.As smartphone screens have edged out TV as the most important real estate for media,companies have invested more in"branded content"-corporate-sponsored media,such as an article or video,that resembles traditional entertainment more than it does traditional advertising.Some of the most prominent names in journalism,such as The New York Times,BuzzFeed,Vice,and The Atlantic,are owned by companies that have launched their own branded-content shops,which operate as stand-alone divisions.As many media companies have tried to become more like advertising companies,the value of the average"creative-account win,"an ad-industry term for a new contract,has declined,falling by about 40 percent between 2016 and 2017.So there are two major themes of the decline of advertising jobs,one that has to do with the companies that now create them and one that has to do with the way brands prefer to market themselves nowadays.In short,the future of the advertising business is being moved to technology companies managing ad networks and media companies making branded content-that is,away from the ad agencies. The underlined phrase"the companies"（Line 2,Para.6）mainly refers to