Hockey legend Wayne Gretzky, when asked for the secret of his success, said, "I skate to where the puck is going to be, not where it has been." That's a lesson that applies equally well to the realm of investing. Investors can look to teens to understand how the consumers of tomorrow are spending their hard-earned cash, which could provide insight into the potential for success or failure going forward.

Piper Jaffray recently released the results of its semiannual Taking Stock With Teens survey, which seeks to understand the spending habits and favored brands among teenagers. The brokerage house surveyed 9,500 teens across 42 states, with an average age of 15.8 years and average household income of about $65,400.

Here are a few of the biggest investing takeaways identified by the survey.

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Image source: Getty Images.

1. Chicken sandwich and a cup o' joe

Not surprisingly, food and drink continued to be the highest spending category among teens, consuming 23% of their disposable income and accounting for the No. 1 priority among males and No. 2 priority for females (clothing was No. 1 for the fairer sex).

Privately held Chick-fil-A was the favorite destination for teen dollars -- voted the top restaurant -- with second place going to Starbucks (NASDAQ:SBUX). The coffee purveyor maintained its double-digit mindshare with upper-income teens (11%) as the "most preferred public company," illustrating the power of the company's brand, which it has been able to leverage into favored status among up-and-coming consumers.

2. Top e-commerce destination

More than half of teens surveyed said Amazon (NASDAQ:AMZN) was their "favorite e-commerce site," dominating the competition with a whopping 52% of the vote. This was an increase from the spring survey, in which Amazon garnered 50%. The survey noted that Amazon's mindshare is 13 times higher than that of its next closest online competitor, which is Nike. Amazon Prime was also a preferred brand among teens. The study also revealed that Prime adoption had grown to 78% for the fall survey, up from 74% at the same time last year.

In addition to being the top overall digital store, Amazon also placed firmly in the top five as a destination for beauty products, though it was still significantly behind Ulta Beauty (NASDAQ:ULTA) and privately held Sephora, which nabbed the No. 1 and No. 2 spots with 38% and 26%, respectively. This shows that Amazon is becoming a force to be reckoned with in the beauty category. It's worth noting, however, that 91% of teens still prefer to shop for beauty products in store rather than online, giving Ulta and Sephora a considerable edge over their digital rival.

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Image source: Getty Images.

3. The decline of cable continues as streaming adoption grows

There's little doubt that teens are among the most active users of streaming video technology, which was again confirmed by the data. Alphabet (NASDAQ:GOOGL) (NASDAQ:GOOG) subsidiary YouTube earned the top spot, while Netflix (NASDAQ:NFLX) came in a close second, but has been trending downward over the past several surveys, dropping from 39% in the first half of 2018 to 35% in the current results. At the same time, YouTube has been increasing its share of video consumption to 37% of the vote, up from 30%. This was the first time Netflix has ceded its long-held lead.

Other video destinations cited in the survey were Disney's (NYSE:DIS) Hulu and Amazon Prime Video, which were both flat with 7% and 3% of the vote, respectively. Also of note is that cable continued its inevitable decline, falling to 12% from 14% earlier this spring.

The results come on the brink of a shifting landscape, with both Apple and Disney set to debut namesake streaming services with Apple TV+ and Disney+ in the coming weeks -- which could potentially disrupt the results of this part of the survey six months from now.