Perhaps the allowed signature styling should change with activity score / membergroup. Like:
- Newbie: No styling (including links) allowed. Max 40 characters.
- Jr. Member: Links allowed. Max 100 characters.
- Member: Unlimited length.
- Full: Color allowed.
- Sr. Member: Size allowed
- Hero: Background color allowed
Then newbies will be less effective advertisers, which would hopefully significantly reduce the incentive for low-content posts. And when people become capable of effectively advertising through their signatures, they'll have invested a lot of time into their accounts, and they won't risk being banned by spamming.
Can this be stickied somewhere please?
I think that's a fair change, the vast majority of the spam is definitely from Jr member/member accounts. I restricted my promotion to 50+ activity for the last two rounds but it doesn't take very long to get 50. I did make some attempt to disqualify spammers but it was pretty much near impossible to thoroughly look into individual users. What would kill spam completely is probably basing the payments off activity which I'll look into doing if I continue this promotion. If you'd like me to stop doing this entirely I'd be totally willing to cancel it, there are already many competitors though.
Basing it off activity wont really work for you or users.