I think here in bitcoin you cannot have an steady income because even in a signature campaign you are not sure that you are going to have an income every week, uncertainty is the idea of bitcoin, everything is unpredictable. I experience joining in campaign then suddenly after a week it closed I was expecting an income from it so sad that I cannot depend on it.
Correct even you received same amount of bitcoin weekly in signature campaign and i think it would not considered as stable income because first of all value of bitcoin is not stable and the signature campaign is not forever some of them are only running in just a month. Much better for now is to have a regular job while working in bitcoin.
Yes earning from signature campaign is temporary and you cannot depend on it for a lifetime to earn bitcoins as you never know when it will stop or disappear so its better to find concrete and regular methods to earn bitcoin which is possible only with full time job and bitcoin can be treated as an extra income.