What exactly would be the purpose of Palin trademarking her name?

It doesn't seem to me that it could really give her grounds to charge/sue people just for mentioning her (it's not like corporations get that ability from trademarking their names), and if I'm not mistaken, there are already laws that would allow her to seek compensation from anybody who profits from the use of her name or likeness without her permission. So what exactly does trademarking it do?