Next week Millar will move to San Francisco to focus on the company's global expansion.
"At the moment the expansion plan is definitely to go to the US and really focus on the global strategy because there are so many business leaders in the US who we want to be sharing this long-form education content with," he said. "At the same time I think Australia is very interesting, as is Europe, so we will definitely look at those markets as well."
The company was preparing to make a deal with an Australian investor within the next few weeks.
Millar said Branson was the reason he got into business.
"He was singlehandedly responsible for that decision so it has always been my dream to meet him," Millar said. "He was pretty chuffed to see I even had a tattoo of his famous phrase 'Screw It, Let's Do It'."
During the interview Branson discussed philanthropic work and business advice.
"It was quite interesting because we talked a lot about the early days of his first business, getting started and the challenges he experienced, and about his philanthropic focus and where he is going with that and the influence he is making - it's very inspiring," Millar said.
"One of the things that stuck out was that I asked him what was the greatest lesson he learned from Nelson Mandela, as they were personal friends - he said forgiveness.
"He said he doesn't think there has ever been a time in business where he has had a falling out with someone where he hasn't rung up, gone out for lunch and sat down to sort it out," Miller said.
"I think that's a great piece of advice for any business leader - don't burn bridges, forgive people when you make mistakes and move on."
Millar said that in the next 10 years he hoped to continue to grow companies.
"I'm not quite sure whether that will be Unfiltered or other businesses, but I have a massive passion for business and entrepreneurship and definitely want to keep starting businesses around the world - hopefully the US will enable me to do that."
Millar believed the interview with Branson would aid Unfiltered's expansion and he was ready to promote it worldwide.
Unfiltered has hosted interviewees including beer baron Sir Douglas Myers, global jeweller Sir Michael Hill, My Food Bag co-founder Theresa Gattung and Prime Minister John Key.