Running your own and being the sole user is the exact same thing as using a dns server (you need to obtain nameservers for any given domain which you have to contact a dns server for).
Except that your queries are spread out to different places instead of all being sent to a single server.
You ask .com resolver for domain.com's NS, and then you ask ns1.domain.com for foo.domain.com. Then you browse to wikipedia.org, and none of those DNS queries go to the same place as the previous site.
