I write under a pen name. It doesn't mean I hide my real name. I still use that on Facebook and people can google either name and they are linked. I picked a pseudonym really because I thought it was cool. Yes, I wanted to stand out and I didn't like that my Surname is like Christopher Pike. I always hated his books. I didn't want to be anywhere near him in the library. Also, I'm a teacher and I write romance. I wanted to draw a line in the sand where I began as a teacher and where the author me started. This does mean I'll never see my name on a shelf in a book store but that has never bothered me. I go by a nickname most of the time and I haven't used my full name since I was about ten. Besides the writing was my passion not seeing the glory of my name published.
That is my story but here is why I think almost every author needs a pen name. There are a few that can skate by because their name is unique but I run another site on New Zealand authors. Today I got sent a list of about 100 authors who are Kiwis and it was recommended I put them on my site. Great, awesome. I'll get on it right away. So I jump on Amazon. About a quarter of those names don't have books on Amazon. I have a love hate relationship with Amazon but they are by far the largest retailer of books in the world. If you aren't on their site you have to wonder. So unless someone asks specifically for me to put them on my site the threshold to be on my site is that you are selling books on Amazon.
Another quarter of those authors get lost in the crowd. Because there is a famous author with the same name. So while you have books about fishing there is another person with your name who sells crime thrillers.
Of the ones I did find a quarter of those didn't have author pages. Just a lone book on Amazon. No Author Bio. No, list of your other books. It makes me sad when I see these. Technology is leaving behind some really good authors because they can't sign up for things and do promos or claim pages on Amazon or Goodreads.
Of course this wouldn't have mattered if they had a truly unique name. I beg, I plead authors google your name before you publish.