After law school, in 1993, he and a college friend, Brad Keywell, borrowed money from relatives to buy Brandon Apparel, a clothing company in Madison, Wisconsin.. In 1999, they created an Internet company, Starbelly, that specialized in promotional products. The firm was sold to Halo Industries in January 2000, with Lefkofsky joining Halo as chief operating officer. A little more than a year later, the company went bankrupt, and the firms faced multiple lawsuits from shareholders, all of which were resolved by 2004. Lefkofsky then co-founded InnerWorkings in fall 2001, a firm providing print procurement services for mid-sized companies; In August 2006, it had an initial public offering. Lefkofsky was on its board of directors until October 2012. In February 2005, Lefkofsky and Keywell created a freight logistics company, Echo Global Logistics. It attracted financing from New Enterprise Associates, and went public on the NASDAQ under the symbol 'ECHO' in June 2006. In June 2006, Lefkofsky and Keywell founded MediaBank, a company providing technology for advertising buyers. In June 2007, the firm acquired Datatech, a media planning and procurement platform. In July 2007, New Enterprise Associates invested in MediaBank. In 2012, a merger between MediaBank and Donovan Data Systems created Mediaocean, in a deal estimated at $1.5 billion. In January 2007, Lefkofsky co-founded and provided $1 million in funding for ThePoint.com, an collective action website started by Andrew Mason, and New Enterprise Associates led an early stage investment round. In late 2008, the site changed its name to Groupon.com. In October 2009, Groupon raised $30 million from Accel Partners and New Enterprise Associates. In April 2010, Digital Sky Technology and Battery Ventures invested $135 million in Groupon at a valuation of $1.35 billion. In August 2010, Forbes reported that it was the fastest growing company in history. In December 2010, Google offered a reported $6 billion for Groupon. The offer was turned down, possibly due to anti-trust and regulatory scrutiny the deal might face. In October 2011, Groupon raised $950 million in private funding and then paid $810 million to employees and investors. Lefkofsky and family were paid $398 million. In August 2013, Lefkofsky became CEO of Groupon; in November 2016 he stepped down as CEO, resuming his role as Chairman. In July 2014, Lefkofsky was an early investor in Uptake, LLC, an analytics company. In 2016, Lefkofsky founded Tempus, a technology company that enables physicians to deliver personalized cancer care, and serves as its CEO.
Philanthropy
In 2006, Lefkofsky and his wife, Liz, formed a private charitable trust, The Lefkofsky Family Foundation. Its purpose is to advance high-impact initiatives that enhance the quality of human life in the communities they serve. To achieve this mission, the Foundation strives to; ensure access to quality education with a deep focus on the middle grades, improve fundamental human rights for women, girls and communities impacted by violence, propel innovative medical research, and expand cultural initiatives. The foundation has helped fund more than 50 organizations to date. In 2013, Lefkofsky and his wife joined The Giving Pledge.