What I want to say is, it's a good thing if theymos make a system that has a continuity for this reporting system, so users will be motivated to report, even if they dont like it so much. LoyceV's idea of adding new rank when lot of people already have the highest rank is great. It is a form of continuity too, my idea is resetting counts per certain time, maybe like per 6 months or per year.
I doubt we need additional motivation for people who otherwise don't care about the forum enough to report spam. Just like the sig-bounty "motivation" to create shitposts this would just cause new headaches. It's a recognition badge for people who are already motivated and let's leave it at that.