I generally advise against it today, because of the online marketing needed for visibility. It seems doubly complex with needing two email addresses, business cards, a different blog identity,and so on. Read the full article here.
As the article states:
The minute you decide to take on a nom de plume, be prepared to stick to that name in your correspondence and at writers’ conferences and book signings. You want people to associate that name with you, not give them a slew of different names to remember.Thanks to Ronnie at Writer's Relief.
Hint: If you do choose to go with a pen name, choose a name that’s not too generic or linked to someone else. Try an online search of your prospective name to see what comes up.