Celebrity endorsements are hardly novel: Brooke Shields hawked Calvin Klein jeans in the '80s, Bing Crosby crooned about StarKist tuna decades before that, and still today, the Kardashians push dozens of brands at a time.
However, social media's role in influencer marketing has changed the playing field. Consumers no longer trust their favorite celebrities' recommendations as much as they do their favorite YouTubers'. And brands are taking note. According to the State of Influencer Marketing 2017 report, the tactic exploded in growth last year, with almost 90 percent of marketers implementing influencer campaigns and spending between $25,000 and $50,000 to do so.