The name of a business, brand or trademark that is known well enough that it also doubles as traffic generating keyword from search engines.
Our company's main traffic generating keyword is the name of our brand itself.
That guy's online business is so well known that he doesn't need to compete for keywords anymore. People just look up his Brandword
Since millions of people now search the term "oldspice" into Google, it's not a brand anymore. It's a Brandword