< PrevNext > 85. WPP London Share 2016 U.S.-Booked Air Volume: $52 millionWPP's air travel decreased 3 percent year over year to 571 million miles in 2016. The multinational advertising and PR company could owe that to cost pressures like foreign exchange on the cost of travel, according to its sustainability report, and an increase in the use of videoconferencing. Air travel represents 37 percent of WPP's carbon emissions and produced 92,445 tons, a 7 percent decrease from 2015. The company offsets all air travel emissions by purchasing carbon credits. In 2016, it invested £150,000 (US$194,027) to support four renewable energy-generation projects. WPP also added 20 videoconferencing units, increasing the total to 720 in 173 cities. BTN estimates WPP's 2016 U.S.-booked air volume remained the same as in 2015, at $52 million. Revenue in 2016 increased 18 percent to £14.4 billion. WPP acquired 56 companies in 2016 and spent £600 million net of cash on initial acquisition payments, according to the company's annual report. At the end of 2016, WPP operated 160 companies with 132,657 employees, up 6 percent from the previous year's employees.