I believe there is a strong argument that how you represent yourself online can also determine your overall success in your websites performance. I have been a member of several websites over many years and I can easily distinguish who I would do business with or who's website I would join and contribute too.
I'm not sure webmasters, admins and moderators realize what they say and contribute on other websites are really also representing their own websites. If you are a owner of a website(s), admin or moderator and you generally post share and contribute at other website(s), your opinions, your general vibe, your ability to discuss a controversial topic, is always on display for others.
As I discussed on my other website Friend's Realm about two hot spots of mine in both The Downside to Assigning Labels to People and Branding Oopsies, there are many reasons that one should keep their temper in check, carefully reply to polarizing topics and try to be as respectful as possible. This doesn't mean you can't be genuine, but there are ways to handle conflict or disagreements on line that does not result in bruised egos or worse, you have now compromised your brand by the negative way you handled yourself online.
The other aspect of your personal brand, is if you are involved in a website where you post regularly but are also in business for yourself, you should always post thoughtfully. If you post regularly on this website and include in your signature, your business name and contact information, it's always a good idea to remember that you are representing yourself and your business. I have been among this scenario in a website and had considered hiring one of these members, however, by their outlandish behavior, combative vibe and a level of bullying to other members by this member, I decided that I would not be hiring this member for services.
What I also see, is that members in business or website owners will use a common alias for their name. There is nothing wrong with aliases, but always remember your aka with your signature link carries with your behavior online at all of the websites you participate in. People will likely gravitate to a member that is polite, navigates a tough topic with care and also doesn't beleaguer, disrespect or bully other members.
I frankly, see these less then stellar forms of behavior online all of the time. When you are in a place of owning a business, admining or moderating a website, you are always on stage and represent yourself. When you represent yourself well, with kindness, appropriate light-hearted fun, share information without being superior, members/people will appreciate your style and gravitate to your website to chat or seek out your business for services.