Millionaires are liking Facebook, but no longer following Twitter, reports Robert Frank for The Wall Street Journal. A new study shows that 46% of online users with investible assets of $1 million or more are members of Facebook, up from 26% a year ago.

The Spectrem Group survey also showed that millionaires’ already low use of Twitter has declined even more, from 5% to 3%. As for LinkedIn, only 19% of them are using the professional networking service–that’s unchanged from a year ago.

Why aren’t these business-minded people using LinkedIn and Twitter more? “One reason may be that Twitter is a more open network, which makes it more difficult for control-freak millionaires to manage who follows them. On Facebook, you can more easily manage access to information,” writes Frank.

Age is another factor. The study found that among those with $5 million or more in investible assets, the boomers are slightly more likely to use Facebook than the youngest investors–with them Twitter was generally more popular.

Read more at The Wall Street Journal ^[1].