How do campaigns work?
Basically ICO/Websites uses our signature for advertising. Each signature campaign has its own rules and regulation.
Can the posts be about anything and can you be part of multiple signature campaigns?
It will still depend on the rules of the campaign but the posts should be constructive and not spam, there are also some signature campaigns that allow multiple signature.
How do I get paid for it?
Once you are able to qualify for the payment they will send it in BTCor in some cases Altcoin.