One good solution to this problem is as following:
* In order to post content, accounts must be purchased based on a spot fee. For example, if suddenly 10 fold more people want to open accounts then spot price will rise to 60 dollars from a base price of 6 dollars.
* This can be done through BTC payments instead of dollars to protect identity of account owners a bit.
* Users should be able to hand-select moderators and if wanted, review their actions transparently. This will eliminate all unfair moderation and provide huge value to users. An user still can get banned by a moderator but only people who subscribe to that moderator will assume user is banned.
* As accounts are bought to post content, there won’t be any advertisement. There might be some subscription fee though.
* All this can be done in a decentralised framework to increase resilience.