Prior to joining Vonage, Lefar was the principal consultant of Marketing Insights, a technology and media consultancy, which he founded. During this time, he served as senior advisor and operational expert to McKinsey & Co., actively engaged on private equity transactions and hedge fund advisory services in telecom, media and entertainment.

From 2003 to 2007, Lefar served as Chief Marketing Officer for Cingular Wireless (now AT&T Mobility), responsible for all aspects of marketing strategy and execution, including advertising and media, product management, pricing, business development, customer lifecycle management, national promotions and merchandising, market research, and business analytics. Lefar played a major leadership role in the acquisition and successful integration of AT&T Wireless into Cingular in 2005. And, he was one of the lead executives in developing the relationship with Apple for the exclusive iPhone, working directly with Steve Jobs. During his tenure, his team drove Cingular's data business more than tenfold to $7 billion.

Prior to joining Cingular (AT&T), Lefar served as the Chief Marketing Officer of Cable and Wireless Global, where he was responsible for all aspects of marketing across a dozen countries. Lefar has also held senior leadership roles at Verizon Wireless and GTE Wireless.

Lefar began his career at Procter & Gamble. During his nine years at P&G, he held positions of increasing responsibility in both finance and brand management in the U.S. and Eastern Europe.

In 2011, Lefar was appointed as a member of the President's National Security Telecommunications Advisory Committee .

A native of New Jersey, Lefar has a B.S. in Commerce from the McIntire School of Commerce at the University of Virginia. He has served on the Board of the Make-A-Wish Foundation Georgia and Alabama for five years, and is an advisor to the Children's Healthcare of Atlanta Wellness Program, focused on reducing childhood obesity. He currently resides in Atlanta, Georgia, and Red Bank, New Jersey.