I notice that some coins that are already in the market are doing bounty campaign again like Credits, Veil Eterbase and among others, do you think it's important for a coins/tokens that are already listed to run a bounty campaign from time to time even if they are already listed in exchanges.
I don't think it's a problem to me.
A coin that was listed on exchange is more reliable than IEO, ICO projects, cause bounty that you receive could be sold right away. So it's more reliable but you will not receive as much as others, after all, it's all your choice.