earning from signature campaigns is free way to make Bitcoins, but it depends with the member's rank , the campaign rules, need time and effort like the other jobs, and also need some knowledge about bitcoin
There's nothing free about it. To get paid you need to comment, and to get any decent amount you need to make enough comments. To make minimum wage, you would need 400 posts per month depending on your country. That's insane in my book, it takes a lot of energy to keep a good posting rate. So you are trading energy and time which converts in money, therefore not free.