There are for sure other bot management strategies out there (Web Environment Integrity is strictly hypothetical for now, iirc) but the problem is that those st

There are for sure other bot management strategies out there (Web Environment Integrity is strictly hypothetical for now, iirc) but the problem is that those strategies cost money, and often quite a bit. Which, I guess "pay $1 to sign up" is _also_ a strategy that costs money, but that cost gets passed to users :P Honestly though, $1 almost seems too low to be effective in that regard, at least relative to the specific risk/reward of Twitter. For a small forum or something, sure... but if you were interested in running automated Twitter accounts, and you knew for sure that you wouldn't get caught, $100/year to run 100 accounts is absolutely worth it so long as those accounts bring in some kind of money via whatever scam/spam/promotion crap you're running.