How much would you pay for a one-on-one with Richard Branson?

Online charity company Charitybuzz is auctioning off exclusive opportunities to meet with some of the world's top business leaders as a part of Global Entrepreneurship Week. The more than 50 auction participants include Branson, Michael Bloomberg, Warby Parker co-founder Neil Blumenthal, Shark Tank host Lori Greiner, and hip-hop mogul Russell Simmons. Each entrepreneur chooses a charity to receive the proceeds of their auction. 

Charitybuzz, a for-profit business, donates 80 percent of funds raised, and keeps the rest. This is the company's first auction built specifically around entrepreneurs.

At least one previous Charitybuzz auction winner has gone on to land an investment from a celebrity entrepreneur. In 2013, small business owner Julie Bradfield used a one-hour meeting with Shark Tank's Greiner to pitch her travel product company RunningBuddy, which makes a line of magnetic pouches for runners. Greiner invested in the business in July 2014, and the company has generated nearly $2.5 million in retail sales since.

Though Charitybuzz has raised money for experiences involving celebrity entertainers like Mick Jagger, Lady Gaga, and Justin Bieber, entrepreneurs have become some of the company's most sought after individuals. A meeting with Michael Bloomberg even outsold an auction to meet actor George Clooney, according to Charitybuzz founder and CEO Coppy Holzman.

"The new rock stars and celebrities on the internet, and particularly on Charitybuzz, are business leaders and tech moguls," Holzman says.  

Charitybuzz's highest-grossing auction is a 30-minute coffee meeting with Apple CEO Tim Cook that sold for $610,000. A tour of Facebook with director of product Blake Ross, also the co-founder of Firefox, recently sold for $70,000. Cook's auction raised money for the Robert F. Kennedy Center for Justice and Human Rights, while Ross's went toward the Peace Corps Morocco Country Fund.

New York-based Charitybuzz was founded in 2005. Last month, Mark Cuban's longtime business partner and co-founder in, Todd Wagner, acquired a majority stake in the business for an undisclosed sum. Wagner is the founder of celebrity video platform Chideo, which also gives 80 percent of funds raised to charity.

Last year, Charitybuzz held 13,000 auctions with its community of bidders, who live in 110 countries around the world. Since its founding, the company has raised $150 million for more than 3,200 foundations and nonprofits. Depending on the results of its Global Entrepreneurship Week auction, Charitybuzz may hold additional themed auctions in the future, Holzman says.  

Bidding for the entrepreneurship auction ends on December 2. Below is a partial list of the entrepreneurs auctioning off private meetings.

  • Michael Bloomberg, founder, Bloomberg LP
  • Richard Branson, founder, Virgin Group
  • John Stumpf, chairman, Wells Fargo 
  • Sara Blakeley, founder, Spanx
  • Lori Greiner, host, Shark Tank
  • Blake Ross, co-founder, Mozilla
  • Neil Blumenthal, co-founder, Warby Parker
  • Clive Davis, chief creative officer, Sony Music 
  • Tommy Hilfiger, founder, Tommy Hilfiger
  • Sean Rad, founder, Tinder
  • Bob Pittman, chairman and CEO iHeartMedia