Comment by 38
its so easy to solve this problem, not sure why anyone hasnt done it yet.
1. build a userbase, free product
2. once userbase get big enough, any new account requires a monthly fee, maybe $1
3. keep raising the fee higher and higher, until you get to the point that the userbase is manageable.
no ads, simple.
Until N ad views are worth more than $X account creation fee. Then the spammers will just sell ad posts for $X*1.5.
I can’t find it, but there’s someone selling sock puppet posts on HN even.