I would suggest to whitelist the good content creators than blacklisting the spammers. I don't know, but I don't think there are 3500 quality content creators who want to use bid bot service, but I know there would be more than 10,000 spammers, and they can always make a new account.

It would take less time to manually select the good content creators than to judge whether a person is a spammer or not.

Recently @minnowbooster applied this process, though not to a complete extent.

But of course, bid bot business will hurt badly if this process is applied, just saying!