Your Facebook Profile is Also a Professional Tool
You might find this answer surprising, especially from a former executive at LinkedIn I'm currently the CEO at Wealthfront. But the short answer is, yes, in many cases, there is a professional necessity for Facebook. Let me first get my obvious bias out of the way. As one of the people who had a hand in building out LinkedIn, I truly believe that there is a valuable and natural separation between your professional identity and your personal identity. As a result, I would counsel any professional to take great care in how they present themselves on LinkedIn. However, Facebook is ubiquitous, and it is an easily accessible and common search engine for people. It is well indexed in search engines like Google. Chances are, if someone is looking for information about you, as a professional, they will definitely see your LinkedIn profile. There is also a strong chance they will end up looking for your Facebook profile as well. Why?, A few reasons really, Facebook offers quite a few tools to control privacy and sharing. A few recommendations to consider, As a final note, Facebook is most useful professionally as an alternate messaging platform for close friends  colleagues. We live in a world where many people split their attention across too many communication channels. As a result, I now know people who only reliably respond to text messages, answering in minutes where an email will sit unanswered for days. I know people who only respond to DMs on Twitter, or messages on WhatsApp. I also know people who only respond reliably to messages on Facebook. So if your goal is fast and efficient communication, it's worth having a channel to your friends and colleagues who prefer Facebook even if you don't., Necessity is a strong word. You can obviously succeed professionally without Facebook. However, I would argue that using Facebook effectively has distinct value as a professional and there are situations where it can be considered a necessity.