I definitely want to agree with you. only relaying on signature campaign is not a smart move. you should have a backup plan for earning bitcoin. if by chance a signature campaign got closed or you didn't selected there then you should have something to do. the best choice for me is altcoin trading..
I don't think unless you are some crazy farmer or will buy like 20 accounts or something - to earn money which will be sufficient.
You will still be better doing your daily job and then buy bitcoin for money earned from it, than trying to earn only BTC.