Despite being squeezed for time, nearly 70% of millionaires use Facebook and other social media sites, a higher percentage than non-millionaires, according to a new poll by investment firm SEI.

In fact, only 17.4% of these high net-worth individuals visit social media sites on a daily basis, the study found. By contrast, 38% of Americans 18 and older had used a social networking site within the previous 24 hours in an August 2010, according to a study by the Pew Research Center. In that report, titled Older Adults and Social Media, 61% of respondents visited social media sites.

Of the SEI study respondents, 50% said they used Facebook, 37% visited YouTube, and slightly fewer than 35% accessed professional network LinkedIn, the poll found. However, 31.8% of those surveyed claim to have no time for social media.

"Wealthy individuals are engaged with social media even more than the rest of the American public," said David McLaughlin, senior managing director for the SEI Wealth Network, a business unit of SEI that provides private wealth management services.

The majority of millionaires view their social networking activity as personal, not a business tool. In fact, 51% said their Facebook account is for personal use, the study found.

This ties in with another report which found that only 36% of CEOs at the world's largest companies are engaging online with external stakeholders through social media, blogs, websites, and other mediums.

CEOs at the top 50 businesses communicated externally in traditional fashion: 93% were quoted in the major global news and business publications and 40% participated in speaking engagements to an external, non-investor, audience, a Weber Shandwick study found. But most CEO online visibility is limited to what is said about them on Wikipedia, which CEOs and their communications teams are not responsible for. Remove Wikipedia, and only 36% are engaged through their company websites or in social media channels in any way, according to Weber Shandwick.

"Strong evidence exists that CEOs are not silent in these turbulent times. They are extensively quoted in the business press, frequently deliver keynote speeches at conferences, and participate in business school forums. But when it comes to digital engagement externally, CEOs are not yet fully socialized, often with good reason," said Leslie Gaines-Ross, Weber Shandwick's chief reputation strategist and online reputation expert. "As we continue to track the rise of the social CEO and chief executives become more comfortable with the new media, we expect that this will change and change fast."