Why pay when you can offer to follow me and I will follow you scheme it's better that way and a win-win situation and you can get people on twitter with similar interests like you which is Cryptocurrency
AFAIK, there's a new rule or policy about following in twitter.
If most people that will follow OP, it's good to his end. But, he can't follow all of them continuously and it has to refresh because there's a limit which is the new policy.
https://help.twitter.com/mr/rules-and-policies/twitter-following-rules