Considering all the talk of how teens are addicted to their electronic gadgets, it's surprising that the hottest toy of 2017 (so far) is resolutely analog. The fidget spinner is a piece of plastic with some stainless steel that doesn't do much else than spin.

For marketers, the important thing about the toy is how it came to prominence. This wasn't a top-down fad like Wham-O's hula hoop in the 1950s or Coleco's Cabbage Patch Dolls in the 1980s. Instead, a variety of companies make fidget spinners and there seems to be no inventor of the device. This bottom-up Generation Z phenomenon was fueled by two things: word of mouth and video.

The rise of the fad tells you a lot about how things catch on with Generation Z. Here are three takeaways:

1. YouTube rules. For teens, no type of media is as popular as YouTube. An eMarketer survey from 2016 found that 91% of teens use YouTube, a figure that trounces Snapchat (66%) and Facebook (61%.) Teens also look up to YouTube stars more than movie stars. Some 63% of teens said they'd try a brand or product suggested by a YouTuber while only 46% of teens said that was true for a movie star. I know from my experience that the teens I know don't watch TV much. Instead, they spend hours cycling through one video after another. I believe the fidget spinner craze started as other recent fads have – by word of mouth – but YouTube videos helped spread that word of mouthwith videos featuring ordinary kids showing off the fidget spinner. Many of those videos got millions of views.

2. Gen Z avoids traditional ads. Gen Zers say they prefer YouTubers to movie stars because YouTube is interactive and "there's a stronger connection between the person and the viewer.” Millennials have driven the rise of ad blockers, but Gen Zers are even more ad-avoidant. A recent survey showed that 82% of them skip or avoid ads versus 65% of Millennials. It's telling that there were never any ads for the fidget spinner. Teens learned about them from friends or they saw videos of other kids using them on YouTube. That said, there is one loophole: Teens have less of a problem with branded content than their Millennial counterparts.

3. Marketing to Gen Z requires a careful approach. Based on the first two points, it would seem like the smart thing to do if you're marketing to Gen Z is to sign up a YouTube influencer to tout your product. That's exactly what many have done. Unilever, for instance, has partnered with Zoella, a British YouTube star, to sell hair-care products. However, the fall of PewDiePie illustrates the dangers of influencer marketing. Earlier this year, the YouTube mega star went rogue and began dropping anti-Semitic "jokes” that prompted Disney to cut ties with him. And that was before the YouTube brand safety controversy.

None of these points mean that advertising or influencer marketing should be off the table. But marketing to Generation Z will require the utmost care and attention to detail. Marketers are still figuring out how to navigate this demo. Meanwhile, the fidget spinner has shown that this generation isn't waiting around to have marketers tell them what to buy.