Resteems - I think the person who cares the most about them is the author of the resteemed post. I never got much exposure when someone resteemed my post, but it was good to know someone actually liked it.

And mentions are pretty useless unless the mentioned user has ginabot ,partiko or another way of getting notifications (who the hell checks steemworld every few hours for mentions).

In my experience, the best way of promoting yourself is hanging out in Discord servers for a looong looong time, then you can catch a few glances of people who are also there...