Yes I also say siganture campaign is one of the best source of bitcoin now a days. Just wait until your rank become member or full member because the payout of that rank is good. You must maintain your post in good quality so if you apply in signature campaign you accept . I dont like faucet because you cannot get good payout by doing it. Unless you have thousands of active referrals thats work for you.
I have never managed to make a one working referral, let alone thousands, so I agree with you, faucets bring almost nothing. I think mining is a pretty good source of BTC but you have to invest over $1,000 first which not many can afford. So, yes, for the people who don't have over $1k to invest, sig campaigns are among the best sources o Bitcoin today. Another good source is when you ask to pay you in BTC for the job you've done, worked for me twice so far.
"It didn't work for me, pretty sure it's not working out for everybody else." How about no? I'm sure that if you put enough effort on finding referrals, you will get active referrals. Simply knowing a friend that's interested in bitcoins gives you one potential active referral. If you don't have someone who's interested in bitcoins, then make them. Talk about bitcoins to them and tell them how much you've made so far.
You don't just post your referral link on Facebook and then expect someone to join you. It doesn't work that way. Others make blog about bitcoin just to get referrals. It's on you how are you going to make people sign up under you.
For mining its need good knowledge of bitcoin or cryptocurrency and other things to start And if you have enough capital to start mining.
Or you can try as freelancer if you have some specific skills.