"Your time management should be spent 50 percent of your time on figuring out how to grow the online business, 25 percent of your time being marketing geniuses, which you guys already are, and then the rest for the locations," he said. "And if one and two aren't right, don't do three."
Rabbani and Williams also mentioned that they had been toying with the idea of franchising. While Lemonis agreed that it can be helpful in building a business, he urged the entrepreneurs to hold off for now.
Read MoreThe $100 million idea that no one knows about
"Franchising's an important thing," he said. "But if you have the capital to do it yourself, you may want to make all the money for your business before you let everybody else make money on your business."
He told them that when the time to franchise rolls around, they should carefully consider whom they sell their business to. He recommended putting future locations in hair salons, where the staff's hair care knowledge is equal to theirs.
"I would much rather be selling my franchise through somebody who knows the business, as opposed to somebody who says, 'Oh, I want to make $20,000, I'll buy one,'" he said.
Read MoreLemonis: Don't sell, It could be the next big thing!
Rabbani and Williams took Lemonis' advice. They have put aside the idea of franchising and focused instead on expanding online, and to sweeten the pot, they gained the endorsement of tennis star Serena Williams.
Follow The Profit's Marcus Lemonis on Twitter: