When they can't have a proper domain name, their can only pay minor amount for each post then how can you expect them to start a signature campaign which involves a lot of money. Marketing isn't easy and free.
You are not making any sense here. They are ready to reward posters with low amounts in their forum and there is no limit on the number of people who can join and post in their forum which adds up to a decent amount.
This is why I suggested a signature campaign which could be better overall. Just because they don't possess a great domain name does not mean that they are short on funds.
So suggesting them to run signature campaign does make senses? If they have enough funds, they should have offered better rate for the pay per post on their forum.
It is simple logic, if they have enough funds then simply increase the pay per post rate instead of signature campaign. Why?
Because higher pay per post rate will bring them more traffic while signature campaign wont be effective if they do not offer good thing on the forum.
Their service is just a forum, brand new forum. Signature campaign requires not small amount of money while they do not have any income by providing the forum. Where is the senses or logic?