NEW YORK (AdAge.com) -- They entered the consumer market during the stormiest economic climate since the Great Depression. And like the generation that was forever altered by the harsh sacrifices of World War II, millennials are likely to be permanently affected by the Great Recession and its long-term ripples. But these characteristics won't change about the demographic: They are vocal, demanding and discerning.

Members of Generation Y -- the demographic loosely defined as those born between 1980 on the early end and 2000 on the high end -- are truly the product of the turbulent times in which they were reared, and present a challenge for marketers who dare target this shrewd and, yes, narcissistic generation.

Today, many millennials are unemployed; according to a Pew Research study released in February, a staggering 37% of 18 to 29-year-olds don't have jobs, the highest share in three decades. Those who can afford to attend college are going to less-expensive state schools or community colleges and many are moving back home after graduation. More than a third depend on family members for regular financial assistance.

They're tightening their belts and re-evaluating what makes them happy -- and they're spending money accordingly.

"We may not have lost jobs now, but we never had them in the first place," said Gabi Gregg, a 24-year-old graduate of Mount Holyoke College who was recently chosen as MTV's first "Twitter Jockey" in a nationwide competition. Ms. Gregg was awarded the coveted $100,000-a-year position -- her first stable job -- in which she's charged with engaging millennials like herself in the topics that matter most to them. "Almost everyone I know is living paycheck to paycheck, just trying to survive. It's easier to interact online than to go out and pay for dinner, or go to a movie."

Paul Taylor, exec VP of the Pew Research Center, said finding footing on the first rung of the career ladder can be the hardest step for Gen Y.

"Young adults who start out in bad economic times suffer long-term consequences," he said. "If you don't find a job right out of college, it may affect you for as long as 10 to 15 years down the road."

Aside from the economic wrench, millennials bear key characteristics that distinguish them: they live and die by social media and peer validation; they were raised in "peer-renting" households that placed them at the center of their families' attention; they're endlessly optimistic about their futures despite current hardships; and they care about social causes -- at least enough to serve up a mean Facebook campaign.

But whether millennials can tangibly unite behind a cause is a key tension point between experts and millennials themselves. Nick Shore, head of research for MTV who's currently conducting a study on the behavior patterns of Gen Y, suggests most millennials are willing to click the "like" button on Facebook to indicate support of a cause, but won't venture too much further beyond the gesture.

This isn't to mean that millennials don't care, though. Experts agree that given their collective upbringing, for Gen Y, negotiation is the new rebellion. "They don't see themselves as revolutionaries or reformers, they see themselves as quiet [agents of] change," said Carol Phillips, founder of the market research firm Brand Amplitude, which specializes in millennial studies. "It's about working within the system. They've never had to reject anything; they've just had to build on it. And their numbers suggest that they can be successful at it."

This is a defining characteristic of the generation, according to author and economist Neil Howe, who coined the term "millennial" in the early '90s in his first of several books on Gen Y. And like most millennial-related issues, technology plays a part. "If you ask a bunch of Gen Xers [born in the '60s and '70s] what they would do if they didn't like where they worked, most would say 'leave.' But if you ask millennials that question, their attitude is, 'Someone will fix it,'" Mr. Howe said. "They'll start IM-ing each other, a few will get Mom and Dad on their cellphones, someone will call the local media, another will alert the congressman. Millennials trust in their institutions more than baby boomers or Gen Xers."

Ms. Gregg cites the massive response to gay rights advocate Dan Savage's recent "It Gets Better" YouTube project as a prime example of millennial might. In just a few weeks, hundreds of videos of LBGT adults and allies, including many millennials, had submitted videos with anti-bullying messages and support for gay youth. (The channel has since been viewed more than a million times.) Gen Y isn't physically storming the castle walls, but Ms. Gregg said that doesn't mean it's not making its voice heard.

Millennials are also perhaps the most analytical and media-savvy consumers ever. Mr. Shore said that, while some characterize millennials as suspicious or cynical of old-school linear marketing ploys, they're just better at seeing through them. "We shoot a beam of content to the audience, and they take it apart like light through a prism. ... Millennials are super-deconstructive of any kind of media messaging."

Mr. Shore said for this reason and others, transparency and authenticity are key in marketing to Gen Y, and he's not alone -- Ms. Phillips said Gen Y has a love/hate relationship with marketing. "They love brands, and they talk about them more than anything else, but they hate the interruptive model of advertising," said Ms. Phillips. "[Millennials] like to see ads tailored to them. It's not that they don't want to see ads, they just don't want to see ads for Cialis."

Ms. Phillips says millennials are now tinged with a sense of frugality that will likely remain for the rest of their lives. Her research suggests they're big into redistribution of materials, into sharing smaller houses and taking public transit or walking. They've dropped their cable and never used landline phones; they're not eating out as much, and they're paying down their debt. Though they will splurge on necessities (which now include smartphones) and rationalize that occasional Coach bag as a career investment, "they'll go online and ask their friends for recs. They're very careful shoppers."

Ms. Phillips says millennials' focus on experience helps explain why social currency is the new gold standard for smart marketers and advertisers. "If I can add value, they'll tell my story for me," she said. "It puts pressure on marketers to go back to their roots -- it's about engaging consumers with your message."

Mr. Shore, who conducts focus groups for new programming with millennials from the earliest stages of a show's creation, said an essential element in making this new concept of social currency work is actually not so new at all -- linear programming, like the MTV Video Music Awards, around which millennials can engage on digital platforms like Twitter. After all, "smart and funny is the new rock and roll," Mr. Shore said.

Mr. Howe said it's no accident that millennials voted for President Obama by a 66% margin: Mr. Obama, who was Ad Age's Marketer of the Year in 2008, relentlessly peddled the most millennial ideas possible -- positivity and inclusiveness. Mr. Howe said these are values that millennials respond to most.

"Gen X slogans were 'No rules, just right' and 'Grab life by the horns,' all very in-your-face," said Mr. Howe. "For millennials, it's 'Yes, we can,' 'Wii would like to play' and 'We're all in this together' from 'High School Musical.' It's a different attitude. It has to be inclusive, and it has to look for a better day."

While experts note millennials are also known for their arrogance, self-centeredness and reliance on technology, Ms. Phillips said marketers and older generations in general would do well to not pander, over-simplify or write them off too quickly. "They get it. They deeply get it," she said. "And where they go, everyone else is going to follow."

5 tips for marketing to millennials

Be fast
For millennials, there's nothing worth saying that can't be said in 140 characters or less. It's not that they can't handle long-form pitches, they just know you can do better. So do better.

Be clever
As Nick Shore, head of research for MTV, said, "Smart and funny is the new rock 'n' roll." Millennials are set to be the most-educated generation on record, with the largest social-media platform (Facebook) having been famously born on a college campus. "With their roots in college culture, it's no wonder eloquence and timing are more prized than ever for this generation. Err on the side of overestimating the millennial -- as the Old Spice campaign shows -- and sometimes they'll surprise you.

Be transparent
Millennials may be arrogant and entitled, but they're not stupid, and they know media exists to sell them things. So rather than pretending your branded beverage isn't conspicuously placed in a TV character's hand to entice them, look for new ways to make it funny. It will ring true with them, and they'll appreciate the honesty. (Need a cue? Look no further than the deliciously self-referential "30 Rock.")

Don't "technologize" everything
By their own definition, millennials are in part defined by their use of and reliance on technology. But marketers should resist the urge to attempt to "speak their language" -- Gen Yers can smell those ploys a mile away. Remember, millennials are digital natives -- they don't use technology; they live it, and they do so subconsciously.

Give them a reason to talk about you
Millennials don't like ads, but they don't mind marketing that's non-invasive, non-interruptive and that adds something to their experience, either online or off. Whether it's a fun and timely iPhone app, a targeted high-profile event or a personalized viral-video campaign, if you want your message to resonate with millennials, give them something to talk about. And if we know the first thing about millennials, talk they will.