< PrevNext > 68. WPP London Share 2018 U.S.-Booked Air Volume: $60 millionWPP's U.S.-booked air volume jumped $12 million in 2018, according to a BTN estimate. Its global employee headcount decreased from 134,428 at the end of 2017 to 133,903 at the end of 2018, and revenue declined slightly from 15.8 billion British pounds to 15.6. In 2018, WPP made 15 acquisitions, according to M&A advisor Results International. One made public was Bomtempo Anahory & Ralha, an independent creative agency in Portugal. According to WPP's annual report, it has purchased and permanently retired almost 1.5 million carbon credits to offset carbon emissions from air travel since 2007. In 2018, the advertising company purchased offsets for 100 percent of its air travel emissions, equaling 85,459 tons of carbon dioxide equivalent.