Gary Vaynerchuk, 38
The self-styled social media marketer has his share of haters for his brash manner, but before you roll your eyes, consider that he’s now on his third successful act: First he built his father’s brick-and-mortar New Jersey wine shop into a $45 million business by bringing it online and creating Wine Library TV, the oddly viral wine-tasting web show. Its success made him a social media marketing guru—which then led to a 10-book deal with HarperStudio. Now he’s focused on VaynerMedia, a digital agency he launched in 2009 that advises the likes of GE and PepsiCo and has grown to nearly 500 employees. Vaynerchuk, an early investor in Twitter and Uber, has also launched a VC fund with Miami Dolphins owner Stephen Ross to invest in startups like Birchbox and Medium. @GaryVee may be loud, but his influence is real, and he isn’t going away.