Last month, an Atlanta-based company called Rubicon Global announced its entry into the rarefied “unicorn club” of startups worth more than $1 billion. Rubicon is not an obvious candidate—it’s in the gritty business of waste disposal. Then again, it’s not a typical garbage company. It has raised about $200 million, and its investors include Leonardo DiCaprio and Chief Executive Officer Marc Benioff. Rubicon’s co-founder and CEO, 36-year-old Nate Morris, has referred to the company’s service, which connects independent trash haulers with businesses that need their dumpsters emptied, as the “Uber of Trash.”