NEW YORK: Millennials have received a lot of attention from marketers in recent years but their focus is shifting as "centennials", the younger brothers and sisters of Gen Y, are reaching adulthood.

A new report from JWT Intelligence described Generation Z, the 12-19 year old cohort "the ambitious, engaged, sensible child" who wants to "create, connect and change".

But its research threw up a number of contradictory attitudes, with, for example, 86% using their smartphone multiple times a day even though 79% agreed that people their age spent too much time connected to digital devices.

And while 68% were as happy shopping online as offline, 67% said they preferred to shop in stores.

TV is still a powerful medium for this age group as 69% watch more than two hours a day, but at the same time 70% said they watched more than two hours of YouTube content daily.

Among the key takeaways JWT Intelligence had for brands was the need to move beyond the mainstream. "Embrace and celebrate niche trends," it advised. "They might be tomorrow's big thing."

Some are already doing this, with fast food chain Taco Bell, for example, already experimenting with Periscope, the live video-streaming app recently purchased by Twitter. It launched a new product, a biscuit taco, via a "newscast" announcing a giveaway for every customer in America on Cinco de Mayo.

"We're always in beta and trying things out," said Melissa Friebe, vp/Taco Bell Insights Lab.

"[Our consumers] are used to living in this world where people are constantly trying something, seeing if it works and making changes," she told Advertising Age.

Her team has spent the past year exploring the differences between Gen Y and Gen Z. "It took some digging," she revealed. "We found that similar themes are manifesting themselves in different ways – they've become even more empowered, entrepreneurial and just creative."

Long-term planning, she added, has become almost impossible. "Five years is just too far ahead because of how quickly culture is changing and how fast this generation is moving."

Marketers targeting this age group will need to become increasingly agile, reacting quickly to cultural shifts, constantly experimenting and making small bets.

Data sourced from JWT Intelligence, Advertising Age; additional content by Warc staff