Does anyone know how Marketo defines someone as "known"?
Is it as simple as, we know their email address? Or is there specific criteria I can set?
Marketo defines a "known" person as any person in your database that is not an anonymous person. An anonymous person is anyone browsing a munchkin-embedded page but you do not know anything about them (ex. email, company name, etc.). Therefore, a known person is anyone in the database that has person data populated, they do not necessarily have to have an email address populated.