Millennials can be a tricky target for marketers. Despite the fact that, according to eMarketer, more than 82% of US internet users 18 to 34 use social networks at least monthly (and that percentage is likely near 100% in target markets), about 84% of millennials say they don’t notice ads on social sites, according to the Lubin School of Business.

So what are the best ways for marketers to penetrate the seemingly impenetrable millennial market? According to a recent survey by the Pivot Conference, the answer may be cause marketing. About two-thirds of the respondents to the Pivot poll agreed that green and socially conscious motivations were one of the top factors that differentiated millennials from other demographic and psychographic groups.

That perception falls in line with research the eMarketer Daily reported on from agency Cone. While interest in cause-related marketing grew among the general population between 2008 and 2010, social and environmental causes had a significantly greater influence on the purchase decisions of millennials than other generations. If marketers are looking for 18- to 34-year-olds’ “susceptibility” to branding, social and green issues are a good place to start, with 85% saying they would switch brands because of such marketing and 73% saying they would try a new brand. According to Cone, moms are also a prime target of cause-related campaigns.

Asked about what kinds of cause marketing brands could provide that would entice them, millennials were most interested in ways they could learn about issues (86%), buy products where a portion of the sale supports a good cause (85%) or donate money to a nonprofit identified by a brand (84%). With that in mind, brands that show a deep commitment to their chosen cause and facilitate learning and changes in a community are more likely than others to succeed. Do you agree?

As someone who follows demographics, I usually enjoy reading new research about the different generations. Right now, I’m researching my next report on millennials, also called Gen Y or—less often these days—echo boomers. The real name for this generation should be what every research firm calls them: Digital Natives.

What makes them so interesting to me is the incredible influence they have on the technologies and applications we use, with MySpace and Facebook as the easiest examples. Millennials (now about 18 to 32) were all over MySpace back in 2006 and 2007. Then Facebook arrived and created a tsunami of social networkers. In 2010, we are now reading that the kids may be leaving Facebook because friending parents and grandparents is just not cool.

Which brings me to some research from Nielsen that popped up recently on baby boomers vs. millennials. It’s another attempt to show marketers that the boomers really aren’t tightwad technophobes. In fact, it makes the point that the top five websites boomers visit are nearly identical to the top five sites for millennials. Only the order is slightly different.

I was interviewed about boomers and their use of technology on CNBC’s “Tom Brokaw Reports: Boomer$!” back in March. Having just written three eMarketer reports on boomers’ behavior online, it was easy to note that boomers see the internet as another tool to help them live their lives better while connecting with family, friends and colleagues of all ages—even if the buttons on their devices seem to get smaller every year.

The point I think that marketers miss when they talk only about generations is that all individuals are at different life stages—which has a more profound effect on what they need and what they desire than their supposed affiliation with an epithet like millennials, or Gen Y or echo boomers. Some young people are already planning their retirement, while some new empty-nesters are shopping for cars and homes that fit their new lifestyle. Many young people are still aspiring to own their first smartphone, right after they land their first job. Many boomers own smartphones so they can check their email or their social network profile.

No one fits neatly into a name, for long. It will be interesting to see what the digital natives flock to after Facebook—no matter what their age.

Three Op-Ed pieces in Sunday’s New York Times were devoted to ICANN’s recent move to allow URLs without Latin characters—a change that each writer agreed would not effect the global virtual village very much. In the US, Latin characters are the norm since English is spoken by about 80% of the population, age 5 and older, according to the US Census Bureau. Within the remaining 20%, Spanish is the dominant language, spoken by about 12% of the population.

While the addition of non-latin characters probably won’t signal any fundamental shift in how most US consumers view the Web, the move by ICANN did get me thinking, however, about the 29 million Hispanic Internet users in the US—and whether US marketers were doing enough to connect with them via Spanish-language sites. For now, the answer appears to be no. Here’s why.

Many marketers have Spanish-language Websites that mirror or complement their brand’s English-language one. According to comScore, about 19% of Hispanic Internet users use Spanish as their primary language, and most visitors are able to choose which version (English or Spanish) of the site they’d like to read.

The problem is many of the Spanish-version sites are lagging behind their English counterparts. According to AOL’s Hispanic Cyberstudy, one-quarter of Hispanic Internet users say they could not do all the same things on a Spanish-language site that they could do on the corresponding English-language site. And 23% agreed that the English-language sites were better or more comprehensive. A small 8.8% felt they got better deals on English-language sites, too.

Realize that it isn’t just Spanish-dominant Internet users who visit Spanish-language sites. The same AOL Cyberstudy found that bicultural and English-dominant Internet users spent time on Spanish-language sites every week, while Spanish-dominant users also went to English-lanaguage sites.

If brands are going to connect online with one of the country’s fastest growing demographics, they are going to have to create equally engaging experiences in both English and Spanish. Those who do will find their efforts rewarded by more positive word of mouth and higher brand loyalty. Half-hearted efforts will reap fewer rewards.

It’s always nice to find new research that supports so much that has gone before. In this instance, I refer to a press release from the Continuum Crew announcing that baby boomers are “emerging as New Social Media Mavens.” The survey covered 700 respondents from the Greenfield Online Panel, ages 35 and older.

My upcoming report, Boomers and Social Media, shows that boomers are flocking to Facebook. The main reason is the same as every other generation has adopted social networking: They want to be connected to family and friends. In fact, boomers are more open to meeting new people through social networks than any other generation, according to a survey by EuroRSCG Worldwide.

With all the boomers crowding on to Facebook, some media outlets wondered if they weren’t chasing away younger networkers. That does not seem to be the case, especially since the Continuum Crew survey found that its empty-nester respondents reported an “unprecedented” number of adult children were moving back home, thanks to the recession. If kids can swallow their pride and move back in with Mom and Dad, they can’t get too picky about sharing a social network.