"Southerne, almost alone among Restoration dramatists, made playwriting pay." DNB. His writing career was focused exclusively on drama, and his two blockbusters, Oroonoko and The Fatal Marriage, made him rich. [Though the DNB doesn't say exactly how--through performance, sale of copyright, or the many published editions?]; DNB also implies that Southerne was what Johnson in a Rambler calls something like a "good-humoured man"--someone who is friends with lots of poets (from Dryden down to Gray) because he wasn't too threatening or too extreme in his views or manners.