I am looking to try out a bounty campaign using signature but I don't see anyone worth my time right now, I do have a question about this, does it make more sense to promote projects that are already trading over those that are not listed on exchange yet? I see so many that aren't listed like whsiperMSG, Valore, Elysian Finance, they don't look like they will be hitting an exchange any time soon.
Only the project owners and those who are paid by the project usually do this. This is similar to those wearing personal signatures promoting their own websites or services. Projects that are not listed, you can promote them if you wish to.
Usually people who are wearing paid signatures are doing this as a side earning or a hobby or simply as a incentive to participate in the forum discussions.
What and what makes you promote a project?.
Usually if the project is legit, long standing and has been in the community. Majority of exchanges and casinos belong to those. But altcoin projects should be promoted with caution, even then you will find scams.