As the first wave of the Digital Generation, Gen Y is truly disrupting the traditional notions of marketing. Brands can partner with Gen Y by understanding what's important to this culturally diverse and life stage-straddling group, and how digital and mobile permeate their lives.

Millennials have come to be known as the over-sharing generation. But after years of broadcasting their lives on Facebook profiles and Twitter feeds under profiles tied to their real names and real lives, Millennials are looking for ways to share their thoughts with fewer consequences. They're still sharing and looking for outlets to send out their thoughts and voices, but there is a new desire for privacy, secrecy, and anonymity in social media. The Facebookers are becoming the faceless.

For better or worse, Millennials are often viewed as a singular group. They are often characterized as a "me-first" generation that would rather spend time "instagraming" their meals than having a meaningful conversation with another human being. Most brands, of course, know this notion is false. Millennials are very much a deep, complicated collection of people whose interests and purchasing patterns are yet to be completely cracked by marketers.

Sometime in the late-21st century, when linguists and anthropologists are working to pinpoint the exact date when the selfie died, they might trace the Moment of Death for the Selfie (at least among a certain group of Millennials) to Nov. 19, 2013. That, of course, was the day when the esteemed arbiters of words and stuff at the Oxford English Dictionary officially named "selfie" the 2013 Word of the Year. Not-so-coincidentally, it was the same day that Millennials around the world let out a collective "ugh," put down their collective camera phones, and rolled their collective eyes so far back …

We're more than a week into 2014, and 2013 has already become a memory. But it was a big year in tech, marketing, and a big year for Millennials (as they officially became a buzzword), and we don't want to let the last 12 months go without looking at the lessons we've learned. Today, we're listing our biggest advice on how to market to Millennials that you should take with you into the next year.

Never underestimate the power of transparency, especially when trying to appeal to Millennials. According to recent research by celebrity branding expert Jeetendr Sehdev, hip-hop superstar Shawn "Jay-Z" Carter has an authenticity problem. The study found that of the 80 celebrities presented to a field of over 1,000 Millennial consumers, Jay-Z was actually the least prominent when it came to purchasing influence.