I've heard of all anime that I've seen, and I have heard of many that I haven't seen yet. I've heard of some I can never see (Sazae-san), and some I don't feel like seeing (Apocalypse Zero, Tekken).
In total, I've definitely heard of more than I've seen.
of course.......hasnt everyone by default? Because there are advertisements all over the place, especially on the anime youve seen....and manga....so you almost have to hear about more than youve actually seen/read.