Email and Twitter are more than sufficient for me. I find the in-app notifications aren’t that useful to me, but folks might have different preferences.
Email should be good enough, but if we want to do something fancy like having badge number to indicate number of new episodes that we haven’t watched or accessed yet.
I like the in-app notifications. I log into this site fairly frequently so it’s nice to be informed of new stuff when I do. It wouldn’t bother me though if it changed to email.