I've consulted on strategy with a small biz that has both their own site and FB, it's absurd how much more attention the FB content gets. It would be absolutely self-destructive for them to not put work into their FB presence.
Who says they don't? Many businesses that have their own domain also have a FB presence.
And then the domain registrar will be the one duped ;)
My personal favourite was the guy who stole sex.com using only a fax on company letterhead.