Earlier quoted context omitted.
> What's stopping a determined spammer paying for accounts? Paid accounts adds a significant overhead to the spamming. Spammers just don't spam for the sake of it, they want to sell people something, legal or not. It's one thing to buy millions of spam accounts for $100 on the dark web. It's another to have to spend $5 bucks a month per account on millions of accounts...
For nation-state actors looking to spread disinformation, paid accounts are effectively free.
For a business, a shill account can be one of the cheapest marketing options.