While I have come to love Primfeed more than Flickr, I noticed that people don't comment as much here. And social interaction is an important part of sites like this.
Adding a levels system with simple rewards would boost commenting alot. Perhaps whenever you get a reply to a comment you made, you'll earn 1 point. After X# of points, you level up and get a reward. Below are some ideas
Levels System Rewards
  • New Trophies/Icons that appear next to your name (like the blue checkmark currently)
  • Font Style/Color options for your name.
  • A limited # of Special Stickers/Gifs you can use to comment on pics.
  • Unique color themes/styles for your UI
  • Credits/Tokens towards ..something fun?