Other than teenagers and young adults, baby boomers (ages 44 to 61) are also heavy users of social networking sites, according to the Entertainment Trends in America study by The NPD Group.

The study found that 41 percent of baby boomers have visited social networks, and 61 percent have been to sites with streaming or downloadable video, Brand Week reported.

With 11,600 consumers surveyed online, the study found more than 57 percent of all Web users have stopped at social networking sites in the past three months. Baby boomers stopped eight times on average in that period.

"There is an older demographic that is shifting over the youth-centric things on the Web. There is a humor to having one's mom as a Facebook friend in some circles. But it's not actually cool for most people," said Doug Akin, evp-brand development at Mr. Youth, Brand Week reported.

NPD's findings reinforced some of the ideas many marketers already know. "Younger brands like Apple and Red Bull have paved the way, and now 'older brands' must realise that there's a more mainstream approach to reaching all types of consumers,” said Akin.

BMW, with an average buyer aged around 45, used Facebook as a channel to promote its new 1-Series earlier this year, Brand Week reported.

However, most brands have done a poor job with putting themselves in front of older consumers. "What we've found is that technology, media and consumer goods are doing a good job of marketing, overall, in social networks," said Jeremiah Owyang, senior analyst at Forrester Research. "But everyone else is failing."

Owyang said that older users use social networks for different reasons than younger ones, and are less likely to leave messages or interact with others. According to a Forrester study earlier this year, 41 percent of those between age 18 and 24 leave comments or create content on social networking sites, while only 14 percent of those 55 or above do so.

"It tells me that younger consumers want to engage, while older (consumers) are there for information, which is a good place for any marketer to be," Owyang added.

According to NPD, baby boomers who are engaging in social networks or streaming video are 15 percent more likely to buy CDs and DVDs than those unengaged. "Overall, these sites offer a great opportunity to marketers at many age levels, but the boomer visits are really a surprise. These things may be targeted to a younger audience, but as we are seeing, there are more older people who enjoy these services," said Russ Crupnick, NPD's entertainment industry analyst, Brand Week reported.