Steemhunt isn't guaranteed.
They upvote the top 100 hunts per day based on the hunt score (ie, votes from hunters) your hunt has recieved. They also upvote 3 of your comments based on your hunter score (which increases as you vote yourself). So, a new person might not get much in the way of their comments, but if they submit a hunt everyone thinks is great, then the next day they should get something for their comments. It's all about interaction.
With the hunts... if there are 300 hunts for the day, 200 will not recieve an upvote.
Hope that helps!