i would say that pretty hard to earn 1 btc per month for free because if only just from faucet rotator i think it's impossible but if you can combine all way how to earn bitcoin such a faucet, signature campaign or etc i guess you will earn up to 1 btc per month
It depends on many factors like which signature campaigns you're using & your account rank.It will take time to uprank your account to Sr.Member to earn some good amount.
Faucets eat a lot of time & you can't earn big amount without referrals.