< PrevNext > 67. Omnicom Group New York City Share 2017 U.S.-Booked Air Volume: $61 millionU.S.-booked air spending at marketing and communications giant Omnicom Group declined nearly 8 percent in 2017, according to a BTN estimate. Omnicom is comprised of advertising agency networks BBDO, DDB and TBWA, along with Omnicom Media Group and the DAS Group of Companies, which collectively operate more than 1,500 marketing, PR and other agencies. Omnicom's business travel contributed to about 158,000 metric tons of carbon dioxide equivalent in 2017, down from 176,000 in 2016. The company encourages the use of videoconferencing in lieu of travel and suggests combining multiple business trips to limit environmental impact. Omnicom's 2017 revenue dropped 0.9 percent to $15.3 billion, with currency conversion rates a factor. Operating expenses decreased 1.4 percent to $13.2 billion while salary and service costs, which include client-related travel spend, dropped 1.7 percent to about $11.2 billion. The company at the end of 2017 had 77,300 employees, down from 78,500 one year before.