Of course you can read the rest of the article, but the gist of it is that, according to a Nielsen Online study, only 40% of the people who post on Twitter this month will still be there next month. But… but… Oprah and Ellen and MC Hammer use Twitter. Surely Ashton Kutcher can’t be campaigning for global prominence on a service that can’t even keep an audience. That’s what you’d be saying if you’re one of those people who actually cares about celebrities and their one-way communication on Twitter.