Nice job, but as some of the other posters have mentioned you should define active both in terms of the last time someone posted & how frequently they post.
You could even create different categories like daily active, weekly active, biweekly active, bimonthly active, monthly active, quarterly active, biquarterly active, semi annually active, annually active, randomly active, rarely active, presumed no longer active, definitely no longer active, no longer active & status of poster unknown, confirmed deceased, and presumed deceased.
I like Kewlj’s suggestion of classifying what type of poster they are so you should create some categories for that too such as mainly gambling, all gambling, all trolling, mainly trolling, 50% gambling & 50% trolling, combo of trolling and gambling more heavily weighted towards gambling, and combo of trolling and gambling more heavily weighted towards trolling.
Anyway those are just some partial ideas for you to take and run with.