Many people know the Gronkowski family through football. Rob Gronkowski, 29, famously nicknamed "the Gronk," is set to become the highest paid tight end in the NFL, playing for the New England Patriots.
But his older brother, Chris Gronkowski, 31, who also played in the NFL, is chasing success off the field as an entrepreneur. Big brother Gronkowski, who once turned down the opportunity to study at the University of Pennsylvania's prestigious Wharton business school to pursue football, is now the founder of a brand called Ice Shaker, which sells stainless steel protein shakers.
Gronkowski appeared on ABC's "Shark Tank" in October 2017 and landed a $150,000 joint investment from Mark Cuban and Alex Rodriguez for a 15 percent stake in the company. His brothers — Rob, Glenn, Dan and Gordie, who have all had professional sports careers — came on the show for moral support.
After appearing on the show, business has boomed: "We had $80,000 in sales when we pitched on 'Shark Tank,' and we've hit over $3 million in sales since then," Chris Gronkowski tells CNBC Make It.