Yes I agree,

I have seen very cool examples of e-mail funnels where they design emails based on how a person engage with them. That will say if you can engage with a new user and walk them through the start then that would 10X increase the stay. Clearly this can be optimized to crazy levels. A new user if they will stay will a lot come down to if they feel they are being appreciated and boosted by someone. Even smaller upvotes makes waves there.