No, of course not.  Most people that are successful online, especially selling on Amazon, don’t put themselves out there publicly and are more behind-the-scenes in their business.  Can it help you if you’re willing to put yourself out there?  Yes, as you can likely relate more to potential customers, build a deeper relationship and create a following.  Is it required?  No, there’s many marketing strategies that can help you sell or succeed without putting your face out there, so you can remain private or anonymous.

Here’s an article that answers this question more deeply.