I'm a proud penname user right here, and I'm hanivg a blast branding the hell out of it. While I did read Kristen's advice, and think it's spot on, I do have a professional career that depends on my being able to have a clear paper and now electronic trail. As a university instructor and future (hopefully) tenured professor, I need employers and other colleagues to be able to find my journal articles, conference papers, and (one day) my academic books when they do a google search for me. I don't want that electronic trail to be muddled with my flash fiction, short stories, and/or the novel(s) I wrote when I should've been working on my MA thesis and dissertation. I made the decision to do this pretty early on, before I had many followers on my blog or on Twitter (Roni Loren's blog helped me to make this decision; she's been very open about the mistake she made in changing her name late in the game, when she had already built up tons of readers and followers), and I did exactly what you mentioned: changed my email address, blog URL, Twitter handle, everything social media related. Jami Gold has also written some good posts on the pros and cons of pennames, which were also useful when I was making the decision.It's funny, about a month into hanivg the pen name, how naturally the idenpillowy has become part of my life. I made sure to choose a name that had personal meaning Lena was my great-great grandmother's name on my maternal side and so it's been easy to latch onto. I don't have any dreams that my writing persona will be impenetrable; I plaster my headshot everywhere, for one. But hanivg an extra layer of protection, particularly in terms of that electronic footprint, means the world to me.Anyway, I think there are lots of silly reasons why people think they need a penname, and Kristen lays those out well. And there are lots of cons to hanivg the penname, like other commenters are mentioned. But there are legit reasons for choosing them. Writers just need to be smart, and plan ahead, if they're going to make the transition.