I earn more than a dollar a day through alt coin mining. It is much more like passive income, but still somewhat risky due to certain factors like difficulty rise, block halving and many other things.
Speaking of which, I look at Bitcoin and other altcoins as a way to make a side income (more of like a hobby) but in reality it can never replace a job (unless you have invested a lot in cloud mining, etc) Signature campaigns have pretty good payouts, but you can never compare them as a real job since you will earn much more with the same.