If you believe a fee would discourage spammers you're wrong. It would only impact the economy as paid posting would become a little less profitable. Instead of 0.1BTC per month a spammer would be getting that - the fee, e.g. 0.08BTC. Still worth it! It would also discourage new users because not everyone is able to pay a fee from the start, while the long time spammers (who just have to be rich by now) would keep doing it anyway.
I think you're wrong and are probably just basing it off the fact that you don't want to have to pay anything to be able to earn here. Do you think a spammer is going to pay $100 to have a signature on each of his 100 accounts? Of course not, but if you can create 100 accounts for free then it will continue to be abused en mass and by people with hundreds of accounts. Charge to have a signature and this abuse will stop almost instantly or be drastically curbed by about 99%. We really can't continue to just let people have dozens to hundreds of accounts because it gets worse day by day and there's not enough manpower or hours in the day to deal with it now, nevermind months down the line as the problem grows exponentially.
You're right about me not wanting to pay if $100 was on the line. My campaign is paying me about $300 a month. Giving $100 upfront to be able to potentially get $300 if I keep posting throughout the month, not get a ban, negative trust, and the campaign doesn't shut down, is not the most lucrative deal, although I'm sure some people would go for it.
Enough with me. I said what I said because there are campaigns that pay people over $1000 a month and I'm pretty sure your $100 rule isn't going to hurt those people.
Can you start to see the problem? Set the fee at $20 a month, you'll only discourage members from joining those low paid campaigns. Set it at $100, the campaigns will be forced to increase the rates because people won't be willing to join them.
If you make the fees low, you'll only reduce low ranked spam and increase the market price of high ranks. Make them too high and you'll make the campaigns hero/legendary exclusive and make those accounts worth more on the market.
Setting fees will make the market adapt like it always does. It will make it harder to earn anything if you're completely broke, starting your forum career, are a low ranked member, or a member of a low paying campaign. What about the spam that comes from the accounts that are being leveled up for sale? How high should the fee be to be just for everyone?
Just imagine you make 10 accounts for 1000$ and get banned after 2 days for shitposting
btw. we have 5 pages of discussion now, please add some input please @theymos.